vb net 2010 - Page 761 - Developer IT

StackOverflowException throws often when .net application built with Debug mode

- by user1487950

I have an application which access an external webservice often, when i are trying to debug it, means debuging in vistual studio. it often throws out StackOverflowException at the webserverice call point. when building in Release mode , the exception thrown out only occasionally. I checked the call stack, looks like there is no recursive call. can you please suggest? thank you very much. call statck attached. [In a sleep, wait, or join] mscorlib.dll!System.Threading.WaitHandle.InternalWaitOne(System.Runtime.InteropServices.SafeHandle waitableSafeHandle, long millisecondsTimeout, bool hasThreadAffinity, bool exitContext) + 0x2b bytes mscorlib.dll!System.Threading.WaitHandle.WaitOne(int millisecondsTimeout, bool exitContext) + 0x2d bytes System.dll!System.Net.NetworkAddressChangePolled.CheckAndReset() + 0x9d bytes System.dll!System.Net.NclUtilities.LocalAddresses.get() + 0x49 bytes System.dll!System.Net.WebProxyScriptHelper.myIpAddress() + 0x27 bytes [Native to Managed Transition] System.dll!System.Net.WebProxyScriptHelper.MyMethodInfo.Invoke(object target, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture) + 0x6b bytes MTOqoHCT.dll!JScript 0.myIpAddress(object this, Microsoft.JScript.Vsa.VsaEngine vsa Engine, object arguments) + 0x91 bytes MTOqoHCT.dll!JScript 0.FindProxyForURL(object this, Microsoft.JScript.Vsa.VsaEngine vsa Engine, object arguments, object url, object host) + 0x3c6e bytes MTOqoHCT.dll!__WebProxyScript.__WebProxyScript.ExecuteFindProxyForURL(object url, object host) + 0x11d bytes [Native to Managed Transition] Microsoft.JScript.dll!System.Net.VsaWebProxyScript.CallMethod(object targetObject, string name, object[] args) + 0x11a bytes Microsoft.JScript.dll!System.Net.VsaWebProxyScript.Run(string url, string host) + 0x74 bytes [Native to Managed Transition] [Managed to Native Transition] mscorlib.dll!System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage msg, int methodPtr, bool fExecuteInContext) + 0x1ef bytes mscorlib.dll!System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage msg) + 0xf bytes mscorlib.dll!System.Runtime.Remoting.Messaging.ServerObjectTerminatorSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0x66 bytes mscorlib.dll!System.Runtime.Remoting.Messaging.ServerContextTerminatorSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0x8a bytes mscorlib.dll!System.Runtime.Remoting.Channels.CrossContextChannel.SyncProcessMessageCallback(object[] args) + 0x94 bytes mscorlib.dll!System.Threading.Thread.CompleteCrossContextCallback(System.Threading.InternalCrossContextDelegate ftnToCall, object[] args) + 0x8 bytes [Native to Managed Transition] [Managed to Native Transition] mscorlib.dll!System.Runtime.Remoting.Channels.CrossContextChannel.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0xa7 bytes mscorlib.dll!System.Runtime.Remoting.Channels.ChannelServices.SyncDispatchMessage(System.Runtime.Remoting.Messaging.IMessage msg) + 0x92 bytes mscorlib.dll!System.Runtime.Remoting.Channels.CrossAppDomainSink.DoDispatch(byte[] reqStmBuff, System.Runtime.Remoting.Messaging.SmuggledMethodCallMessage smuggledMcm, out System.Runtime.Remoting.Messaging.SmuggledMethodReturnMessage smuggledMrm) + 0xed bytes mscorlib.dll!System.Runtime.Remoting.Channels.CrossAppDomainSink.DoTransitionDispatchCallback(object[] args) + 0x8a bytes mscorlib.dll!System.Threading.Thread.CompleteCrossContextCallback(System.Threading.InternalCrossContextDelegate ftnToCall, object[] args) + 0x8 bytes [Appdomain Transition] mscorlib.dll!System.Runtime.Remoting.Channels.CrossAppDomainSink.DoTransitionDispatch(byte[] reqStmBuff, System.Runtime.Remoting.Messaging.SmuggledMethodCallMessage smuggledMcm, out System.Runtime.Remoting.Messaging.SmuggledMethodReturnMessage smuggledMrm) + 0x74 bytes mscorlib.dll!System.Runtime.Remoting.Channels.CrossAppDomainSink.SyncProcessMessage(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0xa3 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RemotingProxy.CallProcessMessage(System.Runtime.Remoting.Messaging.IMessageSink ms, System.Runtime.Remoting.Messaging.IMessage reqMsg, System.Runtime.Remoting.Contexts.ArrayWithSize proxySinks, System.Threading.Thread currentThread, System.Runtime.Remoting.Contexts.Context currentContext, bool bSkippingContextChain) + 0x50 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RemotingProxy.InternalInvoke(System.Runtime.Remoting.Messaging.IMethodCallMessage reqMcmMsg, bool useDispatchMessage, int callType) + 0x1d5 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RemotingProxy.Invoke(System.Runtime.Remoting.Messaging.IMessage reqMsg) + 0x66 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(ref System.Runtime.Remoting.Proxies.MessageData msgData, int type) + 0xee bytes System.dll!System.Net.NetWebProxyFinder.GetProxies(System.Uri destination, out System.Collections.Generic.IList<string> proxyList) + 0x83 bytes System.dll!System.Net.AutoWebProxyScriptEngine.GetProxies(System.Uri destination, out System.Collections.Generic.IList<string> proxyList, ref int syncStatus) + 0x84 bytes System.dll!System.Net.WebProxy.GetProxiesAuto(System.Uri destination, ref int syncStatus) + 0x2e bytes System.dll!System.Net.ProxyScriptChain.GetNextProxy(out System.Uri proxy) + 0x2e bytes System.dll!System.Net.ProxyChain.ProxyEnumerator.MoveNext() + 0x98 bytes System.dll!System.Net.ServicePointManager.FindServicePoint(System.Uri address, System.Net.IWebProxy proxy, out System.Net.ProxyChain chain, ref System.Net.HttpAbortDelegate abortDelegate, ref int abortState) + 0x120 bytes System.dll!System.Net.HttpWebRequest.FindServicePoint(bool forceFind) + 0xb1 bytes System.dll!System.Net.HttpWebRequest.GetRequestStream(out System.Net.TransportContext context) + 0x247 bytes System.dll!System.Net.HttpWebRequest.GetRequestStream() + 0xe bytes System.Web.Services.dll!System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(string methodName, object[] parameters) + 0xc0 bytes Gfinet.Config.dll!Gfinet.Config.Service.cfg_webservice.addOrUpdateProperties(string string, int intVal, Gfinet.Config.Service.PropertiesDataM[] propertiesDataMs) + 0xa3 bytes Gfinet.Config.dll!Gfinet.Config.Service.WSServiceImpl.AddOrUpdateProperties(int setId, Gfinet.Config.Service.PropertiesDataM[] properties) + 0x46 bytes [Native to Managed Transition] Gfinet.Config.dll!Gfinet.Config.Service.ServiceAspect.InvocationHandler(object target, System.Reflection.MethodBase method, object[] parameters) + 0x49e bytes Gfinet.Config.dll!Gfinet.Config.DynamicProxy.DynamicProxyImpl.Invoke(System.Runtime.Remoting.Messaging.IMessage message) + 0x110 bytes mscorlib.dll!System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(ref System.Runtime.Remoting.Proxies.MessageData msgData, int type) + 0xee bytes Tici.Kraps.Services.dll!Tici.Kraps.Services.Configuration.GFINetConfiguration.StoreElement(string application, string category, string id, string elementValue, bool save) Line 303 + 0x55 bytes C# Tici.Kraps.Services.dll!Tici.Kraps.Services.Configuration.GFINetConfiguration.SaveAllInternal() Line 582 + 0x6e bytes C# Tici.Kraps.Services.dll!Tici.Kraps.Services.Configuration.GFINetConfiguration.SaveAll(bool async) Line 434 + 0x8 bytes C# Tici.Kraps.Services.dll!Tici.Kraps.Services.Configuration.GFINetConfiguration.SaveAll() Line 406 + 0xa bytes C# Tici.Kraps.Services.dll!Tici.Kraps.Services.Container.Persistor.Save() Line 59 + 0xc bytes C# Spark.exe!Tici.Kraps.RibbonShell.OnBtnSaveWorkspaceItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e) Line 642 + 0xf bytes C# DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarItem.OnClick(DevExpress.XtraBars.BarItemLink link) + 0x108 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarBaseButtonItem.OnClick(DevExpress.XtraBars.BarItemLink link) + 0x47 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarItemLink.OnLinkClick() + 0x245 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarItemLink.OnLinkAction(DevExpress.XtraBars.BarLinkAction action, object actionArgs) + 0xb3 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarButtonItemLink.OnLinkAction(DevExpress.XtraBars.BarLinkAction action, object actionArgs) + 0x47e bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.BarItemLink.OnLinkActionCore(DevExpress.XtraBars.BarLinkAction action, object actionArgs) + 0x82 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.ViewInfo.BarSelectionInfo.ClickLink(DevExpress.XtraBars.BarItemLink link) + 0x85 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.ViewInfo.BarSelectionInfo.UnPressLink(DevExpress.XtraBars.BarItemLink link) + 0x1e5 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.Handler.BaseRibbonHandler.OnUnPressItem(DevExpress.Utils.DXMouseEventArgs e, DevExpress.XtraBars.Ribbon.ViewInfo.RibbonHitInfo hitInfo) + 0xa7 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.Handler.BaseRibbonHandler.OnUnPress(DevExpress.Utils.DXMouseEventArgs e, DevExpress.XtraBars.Ribbon.ViewInfo.RibbonHitInfo hitInfo) + 0x5f bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.Handler.BaseRibbonHandler.OnMouseUp(DevExpress.Utils.DXMouseEventArgs e) + 0x19a bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.Handler.RibbonHandler.OnMouseUp(DevExpress.Utils.DXMouseEventArgs e) + 0x47 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.RibbonControl.OnMouseUp(System.Windows.Forms.MouseEventArgs e) + 0x95 bytes System.Windows.Forms.dll!System.Windows.Forms.Control.WmMouseUp(ref System.Windows.Forms.Message m, System.Windows.Forms.MouseButtons button, int clicks) + 0x2d1 bytes System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) + 0x93a bytes DevExpress.Utils.v11.2.dll!DevExpress.Utils.Controls.ControlBase.WndProc(ref System.Windows.Forms.Message m) + 0x81 bytes DevExpress.XtraBars.v11.2.dll!DevExpress.XtraBars.Ribbon.RibbonControl.WndProc(ref System.Windows.Forms.Message m) + 0x85 bytes System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) + 0x13 bytes System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) + 0x31 bytes System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg, System.IntPtr wparam, System.IntPtr lparam) + 0x96 bytes [Native to Managed Transition] [Managed to Native Transition] DevExpress.Utils.v11.2.dll!DevExpress.Utils.Win.Hook.ControlWndHook.WindowProc(System.IntPtr hWnd, int message, System.IntPtr wParam, System.IntPtr lParam) + 0x159 bytes [Native to Managed Transition] [Managed to Native Transition] System.Windows.Forms.dll!System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(System.IntPtr dwComponentID, int reason, int pvLoopData) + 0x287 bytes System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(int reason, System.Windows.Forms.ApplicationContext context) + 0x16c bytes System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(int reason, System.Windows.Forms.ApplicationContext context) + 0x61 bytes System.Windows.Forms.dll!System.Windows.Forms.Application.Run(System.Windows.Forms.Form mainForm) + 0x31 bytes Tici.Kraps.Services.dll!Tici.Kraps.Services.Container.DefaultApplicationRunner.Run() Line 41 + 0x17 bytes C# Kraps.exe!Tici.Kraps.Program.Main() Line 105 + 0x9 bytes C# [Native to Managed Transition] [Managed to Native Transition] mscorlib.dll!System.AppDomain.ExecuteAssembly(string assemblyFile, System.Security.Policy.Evidence assemblySecurity, string[] args) + 0x6d bytes Microsoft.VisualStudio.HostingProcess.Utilities.dll!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() + 0x2a bytes mscorlib.dll!System.Threading.ThreadHelper.ThreadStart_Context(object state) + 0x63 bytes mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool ignoreSyncCtx) + 0xb0 bytes mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x2c bytes mscorlib.dll!System.Threading.ThreadHelper.ThreadStart() + 0x44 bytes [Native to Managed Transition]

Read the article

Choosing the right .NET architecture. WCF? WPF/Forms, ASP.NET (MVC)?

- by Tommy Jakobsen

I’m in the situation that I have to design and implement a rather big system from the bottom. I’m having some (a lot actually) questions about the architecture that I would like your comments and thoughts on. I don’t hope that I’ve written too much here, but I wanted to give you all an idea of what the system is. Quick info about the applications, read if you want: I can’t share much detail about the project, but basically it’s a system where we offer our customer a service to manage their users. We have a hotline where the users call and our hotline uses an (windows) application (intranet) to manage the user’s data, etc. The customer also has a web application where they can see reports, information about their business and users, and the ability to modify their data. Modifying data is not just user data like address and so, but also information about the products/services the user has, which can be complicated. The applications will be built on Microsoft .NET Framework 4, with a MS SQL Server 2008 database. There will be a few applications that have to access this database, such as: Intranet application (used by us and our hotline) Customer web application type 1 Customer web application type 2 Customer web application type n different applications) … Now my big problem is what .NET parts I should use for such a system. For the “backend” I’ve considered using Windows Communication Foundation: Would WCF be a good choice? The intranet application will be an application that has to edit lots of records in the database. It has to be easy to navigate using the keyboard (fast to work with). Has a feature such as “find customer, find that, lookup this, choose this and update that”. What would be the best choice to develop this application in? Would it be WPF or good old Windows Forms? I don’t need all of the fancy graphics features in WPF, like 3D, but the application has to look nice (maybe something like the new Visual Studio/Office tools). And the same question goes for the web pages. They have much the same work to do, but not as many features as the intranet application, and not the same amount of data (much less). That is my questions for now. I’m hoping to get a discussion going that will open my eyes to some of these technologies, helping me decide architecture to go with. I would like to say thanks in advance, and let you all know that any thoughts will be much appreciated.

Read the article

Server.CreateObject Fails when calling .Net object from ASP on 64-bit windows in IIS 32-bit mode

- by DrFredEdison

I have a server running Windows 2003 64-bit, that runs IIS in 32-bit mode. I have a COM object that was registered using the following command: C:\WINDOWS\microsoft.net\Framework\v2.0.50727>regasm D:\Path\To\MyDll.dll /tlb:MyTLB.tlb /codebase When I create the object via ASP I get: Server object error 'ASP 0177 : 8000ffff' Server.CreateObject Failed /includes/a_URLFilter.asp, line 19 8000ffff When I create the object in a vbs script and use the 32-bit version of cscript (in \Windows\syswow64) it works fine. I've checked permissions on the DLL, and the IUSR has Read/Execute. Even if I add the IUSR to the Administrators group, I get the same error. This is the log from ProcessMonitor filtering for the path of my dll (annotated with my actions): [Stop IIS] 1:56:30.0891918 PM w3wp.exe 4088 CloseFile D:\Path\To\MyDll.dll SUCCESS [Start IIS] [Refresh ASP page that uses DLL] 1:56:42.7825154 PM w3wp.exe 2196 QueryOpen D:\Path\To\MyDll.dll SUCCESS CreationTime: 8/19/2009 1:11:17 PM, LastAccessTime: 8/19/2009 1:30:26 PM, LastWriteTime: 8/18/2009 12:09:33 PM, ChangeTime: 8/19/2009 1:22:02 PM, AllocationSize: 20,480, EndOfFile: 20,480, FileAttributes: A 1:56:42.7825972 PM w3wp.exe 2196 QueryOpen D:\Path\To\MyDll.dll SUCCESS CreationTime: 8/19/2009 1:11:17 PM, LastAccessTime: 8/19/2009 1:30:26 PM, LastWriteTime: 8/18/2009 12:09:33 PM, ChangeTime: 8/19/2009 1:22:02 PM, AllocationSize: 20,480, EndOfFile: 20,480, FileAttributes: A 1:56:42.7826961 PM w3wp.exe 2196 CreateFile D:\Path\To\MyDll.dll SUCCESS Desired Access: Generic Read, Disposition: Open, Options: Synchronous IO Non-Alert, Non-Directory File, Attributes: N, ShareMode: Read, Delete, AllocationSize: n/a, Impersonating: SERVER2\IUSR_SERVER2, OpenResult: Opened 1:56:42.7827194 PM w3wp.exe 2196 CreateFileMapping D:\Path\To\MyDll.dll SUCCESS SyncType: SyncTypeCreateSection, PageProtection: 1:56:42.7827546 PM w3wp.exe 2196 CreateFileMapping D:\Path\To\MyDll.dll SUCCESS SyncType: SyncTypeOther 1:56:42.7829130 PM w3wp.exe 2196 Load Image D:\Path\To\MyDll.dll SUCCESS Image Base: 0x6350000, Image Size: 0x8000 1:56:42.7830590 PM w3wp.exe 2196 Load Image D:\Path\To\MyDll.dll SUCCESS Image Base: 0x6360000, Image Size: 0x8000 1:56:42.7838855 PM w3wp.exe 2196 CreateFile D:\Webspace\SecurityDll\bin SUCCESS Desired Access: Read Data/List Directory, Synchronize, Disposition: Open, Options: Directory, Synchronous IO Non-Alert, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a, Impersonating: SERVER2\IUSR_SERVER2, OpenResult: Opened 1:56:42.7839081 PM w3wp.exe 2196 QueryDirectory D:\Path\To\MyDll.INI NO SUCH FILE Filter: SecurityDll.INI 1:56:42.7839281 PM w3wp.exe 2196 CloseFile D:\Webspace\SecurityDll\bin SUCCESS [Refresh ASP page that uses DLL] [Refresh ASP page that uses DLL] [Refresh ASP page that uses DLL] This dll works fine on other servers, running 32-bit windows. I can't think of anything else that would make this work. Any suggestions? UPDATE The .dll is not in the GAC, it is compiled as 32-bit, and is Strongly signed.

Read the article

Entity Association Mapping with Code First Part 1 : Mapping Complex Types

- by mortezam

Last week the CTP5 build of the new Entity Framework Code First has been released by data team at Microsoft. Entity Framework Code-First provides a pretty powerful code-centric way to work with the databases. When it comes to associations, it brings ultimate flexibility. I’m a big fan of the EF Code First approach and am planning to explain association mapping with code first in a series of blog posts and this one is dedicated to Complex Types. If you are new to Code First approach, you can find a great walkthrough here. In order to build a solid foundation for our discussion, we will start by learning about some of the core concepts around the relationship mapping. What is Mapping?Mapping is the act of determining how objects and their relationships are persisted in permanent data storage, in our case, relational databases. What is Relationship mapping?A mapping that describes how to persist a relationship (association, aggregation, or composition) between two or more objects. Types of RelationshipsThere are two categories of object relationships that we need to be concerned with when mapping associations. The first category is based on multiplicity and it includes three types: One-to-one relationships: This is a relationship where the maximums of each of its multiplicities is one. One-to-many relationships: Also known as a many-to-one relationship, this occurs when the maximum of one multiplicity is one and the other is greater than one. Many-to-many relationships: This is a relationship where the maximum of both multiplicities is greater than one. The second category is based on directionality and it contains two types: Uni-directional relationships: when an object knows about the object(s) it is related to but the other object(s) do not know of the original object. To put this in EF terminology, when a navigation property exists only on one of the association ends and not on the both. Bi-directional relationships: When the objects on both end of the relationship know of each other (i.e. a navigation property defined on both ends). How Object Relationships Are Implemented in POCO domain models?When the multiplicity is one (e.g. 0..1 or 1) the relationship is implemented by defining a navigation property that reference the other object (e.g. an Address property on User class). When the multiplicity is many (e.g. 0..*, 1..*) the relationship is implemented via an ICollection of the type of other object. How Relational Database Relationships Are Implemented? Relationships in relational databases are maintained through the use of Foreign Keys. A foreign key is a data attribute(s) that appears in one table and must be the primary key or other candidate key in another table. With a one-to-one relationship the foreign key needs to be implemented by one of the tables. To implement a one-to-many relationship we implement a foreign key from the “one table” to the “many table”. We could also choose to implement a one-to-many relationship via an associative table (aka Join table), effectively making it a many-to-many relationship. Introducing the ModelNow, let's review the model that we are going to use in order to implement Complex Type with Code First. It's a simple object model which consist of two classes: User and Address. Each user could have one billing address. The Address information of a User is modeled as a separate class as you can see in the UML model below: In object-modeling terms, this association is a kind of aggregation—a part-of relationship. Aggregation is a strong form of association; it has some additional semantics with regard to the lifecycle of objects. In this case, we have an even stronger form, composition, where the lifecycle of the part is fully dependent upon the lifecycle of the whole. Fine-grained domain models The motivation behind this design was to achieve Fine-grained domain models. In crude terms, fine-grained means “more classes than tables”. For example, a user may have both a billing address and a home address. In the database, you may have a single User table with the columns BillingStreet, BillingCity, and BillingPostalCode along with HomeStreet, HomeCity, and HomePostalCode. There are good reasons to use this somewhat denormalized relational model (performance, for one). In our object model, we can use the same approach, representing the two addresses as six string-valued properties of the User class. But it’s much better to model this using an Address class, where User has the BillingAddress and HomeAddress properties. This object model achieves improved cohesion and greater code reuse and is more understandable. Complex Types: Splitting a Table Across Multiple Types Back to our model, there is no difference between this composition and other weaker styles of association when it comes to the actual C# implementation. But in the context of ORM, there is a big difference: A composed class is often a candidate Complex Type. But C# has no concept of composition—a class or property can’t be marked as a composition. The only difference is the object identifier: a complex type has no individual identity (i.e. no AddressId defined on Address class) which make sense because when it comes to the database everything is going to be saved into one single table. How to implement a Complex Types with Code First Code First has a concept of Complex Type Discovery that works based on a set of Conventions. The convention is that if Code First discovers a class where a primary key cannot be inferred, and no primary key is registered through Data Annotations or the fluent API, then the type will be automatically registered as a complex type. Complex type detection also requires that the type does not have properties that reference entity types (i.e. all the properties must be scalar types) and is not referenced from a collection property on another type. Here is the implementation: public class User{ public int UserId { get; set; } public string FirstName { get; set; } public string LastName { get; set; } public string Username { get; set; } public Address Address { get; set; }} public class Address { public string Street { get; set; } public string City { get; set; } public string PostalCode { get; set; } }public class EntityMappingContext : DbContext { public DbSet<User> Users { get; set; } } With code first, this is all of the code we need to write to create a complex type, we do not need to configure any additional database schema mapping information through Data Annotations or the fluent API. Database SchemaThe mapping result for this object model is as follows: Limitations of this mappingThere are two important limitations to classes mapped as Complex Types: Shared references is not possible: The Address Complex Type doesn’t have its own database identity (primary key) and so can’t be referred to by any object other than the containing instance of User (e.g. a Shipping class that also needs to reference the same User Address). No elegant way to represent a null reference There is no elegant way to represent a null reference to an Address. When reading from database, EF Code First always initialize Address object even if values in all mapped columns of the complex type are null. This means that if you store a complex type object with all null property values, EF Code First returns a initialized complex type when the owning entity object is retrieved from the database. SummaryIn this post we learned about fine-grained domain models which complex type is just one example of it. Fine-grained is fully supported by EF Code First and is known as the most important requirement for a rich domain model. Complex type is usually the simplest way to represent one-to-one relationships and because the lifecycle is almost always dependent in such a case, it’s either an aggregation or a composition in UML. In the next posts we will revisit the same domain model and will learn about other ways to map a one-to-one association that does not have the limitations of the complex types. References ADO.NET team blog Mapping Objects to Relational Databases Java Persistence with Hibernate

Read the article

Metro, Authentication, and the ASP.NET Web API

- by Stephen.Walther

Imagine that you want to create a Metro style app written with JavaScript and you want to communicate with a remote web service. For example, you are creating a movie app which retrieves a list of movies from a movies service. In this situation, how do you authenticate your Metro app and the Metro user so not just anyone can call the movies service? How can you identify the user making the request so you can return user specific data from the service? The Windows Live SDK supports a feature named Single Sign-On. When a user logs into a Windows 8 machine using their Live ID, you can authenticate the user’s identity automatically. Even better, when the Metro app performs a call to a remote web service, you can pass an authentication token to the remote service and prevent unauthorized access to the service. The documentation for Single Sign-On is located here: http://msdn.microsoft.com/en-us/library/live/hh826544.aspx In this blog entry, I describe the steps that you need to follow to use Single Sign-On with a (very) simple movie app. We build a Metro app which communicates with a web service created using the ASP.NET Web API. Creating the Visual Studio Solution Let’s start by creating a Visual Studio solution which contains two projects: a Windows Metro style Blank App project and an ASP.NET MVC 4 Web Application project. Name the Metro app MovieApp and the ASP.NET MVC application MovieApp.Services. When you create the ASP.NET MVC application, select the Web API template: After you create the two projects, your Visual Studio Solution Explorer window should look like this: Configuring the Live SDK You need to get your hands on the Live SDK and register your Metro app. You can download the latest version of the SDK (version 5.2) from the following address: http://www.microsoft.com/en-us/download/details.aspx?id=29938 After you download the Live SDK, you need to visit the following website to register your Metro app: https://manage.dev.live.com/build Don’t let the title of the website — Windows Push Notifications & Live Connect – confuse you, this is the right place. Follow the instructions at the website to register your Metro app. Don’t forget to follow the instructions in Step 3 for updating the information in your Metro app’s manifest. After you register, your client secret is displayed. Record this client secret because you will need it later (we use it with the web service): You need to configure one more thing. You must enter your Redirect Domain by visiting the following website: https://manage.dev.live.com/Applications/Index Click on your application name, click Edit Settings, click the API Settings tab, and enter a value for the Redirect Domain field. You can enter any domain that you please just as long as the domain has not already been taken: For the Redirect Domain, I entered http://superexpertmovieapp.com. Create the Metro MovieApp Next, we need to create the MovieApp. The MovieApp will: 1. Use Single Sign-On to log the current user into Live 2. Call the MoviesService web service 3. Display the results in a ListView control Because we use the Live SDK in the MovieApp, we need to add a reference to it. Right-click your References folder in the Solution Explorer window and add the reference: Here’s the HTML page for the Metro App: <!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title>MovieApp</title>  <link href="//Microsoft.WinJS.1.0.RC/css/ui-dark.css" rel="stylesheet" /> <script src="//Microsoft.WinJS.1.0.RC/js/base.js"></script> <script src="//Microsoft.WinJS.1.0.RC/js/ui.js"></script>  <script type="text/javascript" src="/LiveSDKHTML/js/wl.js"></script>  <link href="/css/default.css" rel="stylesheet" /> <script src="/js/default.js"></script> </head> <body> <div id="tmplMovie" data-win-control="WinJS.Binding.Template"> <div class="movieItem"> <span data-win-bind="innerText:title"></span> <br /><span data-win-bind="innerText:director"></span> </div> </div> <div id="lvMovies" data-win-control="WinJS.UI.ListView" data-win-options="{ itemTemplate: select('#tmplMovie') }"> </div> </body> </html> The HTML page above contains a Template and ListView control. These controls are used to display the movies when the movies are returned from the movies service. Notice that the page includes a reference to the Live script that we registered earlier:  <script type="text/javascript" src="/LiveSDKHTML/js/wl.js"></script> The JavaScript code looks like this: (function () { "use strict"; var REDIRECT_DOMAIN = "http://superexpertmovieapp.com"; var WEBSERVICE_URL = "http://localhost:49743/api/movies"; function init() { WinJS.UI.processAll().done(function () { // Get element and control references var lvMovies = document.getElementById("lvMovies").winControl; // Login to Windows Live var scopes = ["wl.signin"]; WL.init({ scope: scopes, redirect_uri: REDIRECT_DOMAIN }); WL.login().then( function(response) { // Get the authentication token var authenticationToken = response.session.authentication_token; // Call the web service var options = { url: WEBSERVICE_URL, headers: { authenticationToken: authenticationToken } }; WinJS.xhr(options).done( function (xhr) { var movies = JSON.parse(xhr.response); var listMovies = new WinJS.Binding.List(movies); lvMovies.itemDataSource = listMovies.dataSource; }, function (xhr) { console.log(xhr.statusText); } ); }, function(response) { throw WinJS.ErrorFromName("Failed to login!"); } ); }); } document.addEventListener("DOMContentLoaded", init); })(); There are two constants which you need to set to get the code above to work: REDIRECT_DOMAIN and WEBSERVICE_URL. The REDIRECT_DOMAIN is the domain that you entered when registering your app with Live. The WEBSERVICE_URL is the path to your web service. You can get the correct value for WEBSERVICE_URL by opening the Project Properties for the MovieApp.Services project, clicking the Web tab, and getting the correct URL. The port number is randomly generated. In my code, I used the URL “http://localhost:49743/api/movies”. Assuming that the user is logged into Windows 8 with a Live account, when the user runs the MovieApp, the user is logged into Live automatically. The user is logged in with the following code: // Login to Windows Live var scopes = ["wl.signin"]; WL.init({ scope: scopes, redirect_uri: REDIRECT_DOMAIN }); WL.login().then(function(response) { // Do something }); The scopes setting determines what the user has permission to do. For example, access the user’s SkyDrive or access the user’s calendar or contacts. The available scopes are listed here: http://msdn.microsoft.com/en-us/library/live/hh243646.aspx In our case, we only need the wl.signin scope which enables Single Sign-On. After the user signs in, you can retrieve the user’s Live authentication token. The authentication token is passed to the movies service to authenticate the user. Creating the Movies Service The Movies Service is implemented as an API controller in an ASP.NET MVC 4 Web API project. Here’s what the MoviesController looks like: using System.Collections.Generic; using System.Linq; using System.Net; using System.Net.Http; using System.Web.Http; using JWTSample; using MovieApp.Services.Models; namespace MovieApp.Services.Controllers { public class MoviesController : ApiController { const string CLIENT_SECRET = "NtxjF2wu7JeY1unvVN-lb0hoeWOMUFoR"; // GET api/values public HttpResponseMessage Get() { // Authenticate // Get authenticationToken var authenticationToken = Request.Headers.GetValues("authenticationToken").FirstOrDefault(); if (authenticationToken == null) { return new HttpResponseMessage(HttpStatusCode.Unauthorized); } // Validate token var d = new Dictionary<int, string>(); d.Add(0, CLIENT_SECRET); try { var myJWT = new JsonWebToken(authenticationToken, d); } catch { return new HttpResponseMessage(HttpStatusCode.Unauthorized); } // Return results return Request.CreateResponse( HttpStatusCode.OK, new List<Movie> { new Movie {Title="Star Wars", Director="Lucas"}, new Movie {Title="King Kong", Director="Jackson"}, new Movie {Title="Memento", Director="Nolan"} } ); } } } Because the Metro app performs an HTTP GET request, the MovieController Get() action is invoked. This action returns a set of three movies when, and only when, the authentication token is validated. The Movie class looks like this: using Newtonsoft.Json; namespace MovieApp.Services.Models { public class Movie { [JsonProperty(PropertyName="title")] public string Title { get; set; } [JsonProperty(PropertyName="director")] public string Director { get; set; } } } Notice that the Movie class uses the JsonProperty attribute to change Title to title and Director to director to make JavaScript developers happy. The Get() method validates the authentication token before returning the movies to the Metro app. To get authentication to work, you need to provide the client secret which you created at the Live management site. If you forgot to write down the secret, you can get it again here: https://manage.dev.live.com/Applications/Index The client secret is assigned to a constant at the top of the MoviesController class. The MoviesController class uses a helper class named JsonWebToken to validate the authentication token. This class was created by the Windows Live team. You can get the source code for the JsonWebToken class from the following GitHub repository: https://github.com/liveservices/LiveSDK/blob/master/Samples/Asp.net/AuthenticationTokenSample/JsonWebToken.cs You need to add an additional reference to your MVC project to use the JsonWebToken class: System.Runtime.Serialization. You can use the JsonWebToken class to get a unique and validated user ID like this: var user = myJWT.Claims.UserId; If you need to store user specific information then you can use the UserId property to uniquely identify the user making the web service call. Running the MovieApp When you first run the Metro MovieApp, you get a screen which asks whether the app should have permission to use Single Sign-On. This screen never appears again after you give permission once. Actually, when I first ran the app, I get the following error: According to the error, the app is blocked because “We detected some suspicious activity with your Online Id account. To help protect you, we’ve temporarily blocked your account.” This appears to be a bug in the current preview release of the Live SDK and there is more information about this bug here: http://social.msdn.microsoft.com/Forums/en-US/messengerconnect/thread/866c495f-2127-429d-ab07-842ef84f16ae/ If you click continue, and continue running the app, the error message does not appear again. Summary The goal of this blog entry was to describe how you can validate Metro apps and Metro users when performing a call to a remote web service. First, I explained how you can create a Metro app which takes advantage of Single Sign-On to authenticate the current user against Live automatically. You learned how to register your Metro app with Live and how to include an authentication token in an Ajax call. Next, I explained how you can validate the authentication token – retrieved from the request header – in a web service. I discussed how you can use the JsonWebToken class to validate the authentication token and retrieve the unique user ID.

Read the article

WPF Login Verification Using Active Directory

- by psheriff

Back in October of 2009 I created a WPF login screen (Figure 1) that just showed how to create the layout for a login screen. That one sample is probably the most downloaded sample we have. So in this blog post, I thought I would update that screen and also hook it up to show how to authenticate your user against Active Directory. Figure 1: Original WPF Login Screen I have updated not only the code behind for this login screen, but also the look and feel as shown in Figure 2. Figure 2: An Updated WPF Login Screen The UI To create the UI for this login screen you can refer to my October of 2009 blog post to see how to create the borderless window. You can then look at the sample code to see how I created the linear gradient brush for the background. There are just a few differences in this screen compared to the old version. First, I changed the key image and instead of using words for the Cancel and Login buttons, I used some icons. Secondly I added a text box to hold the Domain name that you wish to authenticate against. This text box is automatically filled in if you are connected to a network. In the Window_Loaded event procedure of the winLogin window you can retrieve the user’s domain name from the Environment.UserDomainName property. For example: txtDomain.Text = Environment.UserDomainName The ADHelper Class Instead of coding the call to authenticate the user directly in the login screen I created an ADHelper class. This will make it easier if you want to add additional AD calls in the future. The ADHelper class contains just one method at this time called AuthenticateUser. This method authenticates a user name and password against the specified domain. The login screen will gather the credentials from the user such as their user name and password, and also the domain name to authenticate against. To use this ADHelper class you will need to add a reference to the System.DirectoryServices.dll in .NET. The AuthenticateUser Method In order to authenticate a user against your Active Directory you will need to supply a valid LDAP path string to the constructor of the DirectoryEntry class. The LDAP path string will be in the format LDAP://DomainName. You will also pass in the user name and password to the constructor of the DirectoryEntry class as well. With a DirectoryEntry object populated with this LDAP path string, the user name and password you will now pass this object to the constructor of a DirectorySearcher object. You then perform the FindOne method on the DirectorySearcher object. If the DirectorySearcher object returns a SearchResult then the credentials supplied are valid. If the credentials are not valid on the Active Directory then an exception is thrown. C#public bool AuthenticateUser(string domainName, string userName, string password){ bool ret = false; try { DirectoryEntry de = new DirectoryEntry("LDAP://" + domainName, userName, password); DirectorySearcher dsearch = new DirectorySearcher(de); SearchResult results = null; results = dsearch.FindOne(); ret = true; } catch { ret = false; } return ret;} Visual Basic Public Function AuthenticateUser(ByVal domainName As String, _ ByVal userName As String, ByVal password As String) As Boolean Dim ret As Boolean = False Try Dim de As New DirectoryEntry("LDAP://" & domainName, _ userName, password) Dim dsearch As New DirectorySearcher(de) Dim results As SearchResult = Nothing results = dsearch.FindOne() ret = True Catch ret = False End Try Return retEnd Function In the Click event procedure under the Login button you will find the following code that will validate the credentials that the user types into the login window. C#private void btnLogin_Click(object sender, RoutedEventArgs e){ ADHelper ad = new ADHelper(); if(ad.AuthenticateUser(txtDomain.Text, txtUserName.Text, txtPassword.Password)) DialogResult = true; else MessageBox.Show("Unable to Authenticate Using the Supplied Credentials");} Visual BasicPrivate Sub btnLogin_Click(ByVal sender As Object, _ ByVal e As RoutedEventArgs) Dim ad As New ADHelper() If ad.AuthenticateUser(txtDomain.Text, txtUserName.Text, _ txtPassword.Password) Then DialogResult = True Else MessageBox.Show("Unable to Authenticate Using the Supplied Credentials") End IfEnd Sub Displaying the Login Screen At some point when your application launches, you will need to display your login screen modally. Below is the code that you would call to display the login form (named winLogin in my sample application). This code is called from the main application form, and thus the owner of the login screen is set to “this”. You then call the ShowDialog method on the login screen to have this form displayed modally. After the user clicks on one of the two buttons you need to check to see what the DialogResult property was set to. The DialogResult property is a nullable type and thus you first need to check to see if the value has been set. C# private void DisplayLoginScreen(){ winLogin win = new winLogin(); win.Owner = this; win.ShowDialog(); if (win.DialogResult.HasValue && win.DialogResult.Value) MessageBox.Show("User Logged In"); else this.Close();} Visual Basic Private Sub DisplayLoginScreen() Dim win As New winLogin() win.Owner = Me win.ShowDialog() If win.DialogResult.HasValue And win.DialogResult.Value Then MessageBox.Show("User Logged In") Else Me.Close() End IfEnd Sub Summary Creating a nice looking login screen is fairly simple to do in WPF. Using the Active Directory services from a WPF application should make your desktop programming task easier as you do not need to create your own user authentication system. I hope this article gave you some ideas on how to create a login screen in WPF. NOTE: You can download the complete sample code for this blog entry at my website: http://www.pdsa.com/downloads. Click on Tips & Tricks, then select 'WPF Login Verification Using Active Directory' from the drop down list. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **We frequently offer a FREE gift for readers of my blog. Visit http://www.pdsa.com/Event/Blog for your FREE gift!

Read the article

How I understood monads, part 1/2: sleepless and self-loathing in Seattle

- by Bertrand Le Roy

For some time now, I had been noticing some interest for monads, mostly in the form of unintelligible (to me) blog posts and comments saying “oh, yeah, that’s a monad” about random stuff as if it were absolutely obvious and if I didn’t know what they were talking about, I was probably an uneducated idiot, ignorant about the simplest and most fundamental concepts of functional programming. Fair enough, I am pretty much exactly that. Being the kind of guy who can spend eight years in college just to understand a few interesting concepts about the universe, I had to check it out and try to understand monads so that I too can say “oh, yeah, that’s a monad”. Man, was I hit hard in the face with the limitations of my own abstract thinking abilities. All the articles I could find about the subject seemed to be vaguely understandable at first but very quickly overloaded the very few concept slots I have available in my brain. They also seemed to be consistently using arcane notation that I was entirely unfamiliar with. It finally all clicked together one Friday afternoon during the team’s beer symposium when Louis was patient enough to break it down for me in a language I could understand (C#). I don’t know if being intoxicated helped. Feel free to read this with or without a drink in hand. So here it is in a nutshell: a monad allows you to manipulate stuff in interesting ways. Oh, OK, you might say. Yeah. Exactly. Let’s start with a trivial case: public static class Trivial { public static TResult Execute<T, TResult>( this T argument, Func<T, TResult> operation) { return operation(argument); } } This is not a monad. I removed most concepts here to start with something very simple. There is only one concept here: the idea of executing an operation on an object. This is of course trivial and it would actually be simpler to just apply that operation directly on the object. But please bear with me, this is our first baby step. Here’s how you use that thing: "some string" .Execute(s => s + " processed by trivial proto-monad.") .Execute(s => s + " And it's chainable!"); What we’re doing here is analogous to having an assembly chain in a factory: you can feed it raw material (the string here) and a number of machines that each implement a step in the manufacturing process and you can start building stuff. The Trivial class here represents the empty assembly chain, the conveyor belt if you will, but it doesn’t care what kind of raw material gets in, what gets out or what each machine is doing. It is pure process. A real monad will need a couple of additional concepts. Let’s say the conveyor belt needs the material to be processed to be contained in standardized boxes, just so that it can safely and efficiently be transported from machine to machine or so that tracking information can be attached to it. Each machine knows how to treat raw material or partly processed material, but it doesn’t know how to treat the boxes so the conveyor belt will have to extract the material from the box before feeding it into each machine, and it will have to box it back afterwards. This conveyor belt with boxes is essentially what a monad is. It has one method to box stuff, one to extract stuff from its box and one to feed stuff into a machine. So let’s reformulate the previous example but this time with the boxes, which will do nothing for the moment except containing stuff. public class Identity<T> { public Identity(T value) { Value = value; } public T Value { get; private set;} public static Identity<T> Unit(T value) { return new Identity<T>(value); } public static Identity<U> Bind<U>( Identity<T> argument, Func<T, Identity<U>> operation) { return operation(argument.Value); } } Now this is a true to the definition Monad, including the weird naming of the methods. It is the simplest monad, called the identity monad and of course it does nothing useful. Here’s how you use it: Identity<string>.Bind( Identity<string>.Unit("some string"), s => Identity<string>.Unit( s + " was processed by identity monad.")).Value That of course is seriously ugly. Note that the operation is responsible for re-boxing its result. That is a part of strict monads that I don’t quite get and I’ll take the liberty to lift that strange constraint in the next examples. To make this more readable and easier to use, let’s build a few extension methods: public static class IdentityExtensions { public static Identity<T> ToIdentity<T>(this T value) { return new Identity<T>(value); } public static Identity<U> Bind<T, U>( this Identity<T> argument, Func<T, U> operation) { return operation(argument.Value).ToIdentity(); } } With those, we can rewrite our code as follows: "some string".ToIdentity() .Bind(s => s + " was processed by monad extensions.") .Bind(s => s + " And it's chainable...") .Value; This is considerably simpler but still retains the qualities of a monad. But it is still pointless. Let’s look at a more useful example, the state monad, which is basically a monad where the boxes have a label. It’s useful to perform operations on arbitrary objects that have been enriched with an attached state object. public class Stateful<TValue, TState> { public Stateful(TValue value, TState state) { Value = value; State = state; } public TValue Value { get; private set; } public TState State { get; set; } } public static class StateExtensions { public static Stateful<TValue, TState> ToStateful<TValue, TState>( this TValue value, TState state) { return new Stateful<TValue, TState>(value, state); } public static Stateful<TResult, TState> Execute<TValue, TState, TResult>( this Stateful<TValue, TState> argument, Func<TValue, TResult> operation) { return operation(argument.Value) .ToStateful(argument.State); } } You can get a stateful version of any object by calling the ToStateful extension method, passing the state object in. You can then execute ordinary operations on the values while retaining the state: var statefulInt = 3.ToStateful("This is the state"); var processedStatefulInt = statefulInt .Execute(i => ++i) .Execute(i => i * 10) .Execute(i => i + 2); Console.WriteLine("Value: {0}; state: {1}", processedStatefulInt.Value, processedStatefulInt.State); This monad differs from the identity by enriching the boxes. There is another way to give value to the monad, which is to enrich the processing. An example of that is the writer monad, which can be typically used to log the operations that are being performed by the monad. Of course, the richest monads enrich both the boxes and the processing. That’s all for today. I hope with this you won’t have to go through the same process that I did to understand monads and that you haven’t gone into concept overload like I did. Next time, we’ll examine some examples that you already know but we will shine the monadic light, hopefully illuminating them in a whole new way. Realizing that this pattern is actually in many places but mostly unnoticed is what will enable the truly casual “oh, yes, that’s a monad” comments. Here’s the code for this article: http://weblogs.asp.net/blogs/bleroy/Samples/Monads.zip The Wikipedia article on monads: http://en.wikipedia.org/wiki/Monads_in_functional_programming This article was invaluable for me in understanding how to express the canonical monads in C# (interesting Linq stuff in there): http://blogs.msdn.com/b/wesdyer/archive/2008/01/11/the-marvels-of-monads.aspx

Read the article

A WPF Image Button

- by psheriff

Instead of a normal button with words, sometimes you want a button that is just graphical. Yes, you can put an Image control in the Content of a normal Button control, but you still have the button outline, and trying to change the style can be rather difficult. Instead I like creating a user control that simulates a button, but just accepts an image. Figure 1 shows an example of three of these custom user controls to represent minimize, maximize and close buttons for a borderless window. Notice the highlighted image button has a gray rectangle around it. You will learn how to highlight using the VisualStateManager in this blog post.Figure 1: Creating a custom user control for things like image buttons gives you complete control over the look and feel.I would suggest you read my previous blog post on creating a custom Button user control as that is a good primer for what I am going to expand upon in this blog post. You can find this blog post at http://weblogs.asp.net/psheriff/archive/2012/08/10/create-your-own-wpf-button-user-controls.aspx.The User ControlThe XAML for this image button user control contains just a few controls, plus a Visual State Manager. The basic outline of the user control is shown below:<Border Grid.Row="0" Name="borMain" Style="{StaticResource pdsaButtonImageBorderStyle}" MouseEnter="borMain_MouseEnter" MouseLeave="borMain_MouseLeave" MouseLeftButtonDown="borMain_MouseLeftButtonDown"> <VisualStateManager.VisualStateGroups> ... MORE XAML HERE ... </VisualStateManager.VisualStateGroups> <Image Style="{StaticResource pdsaButtonImageImageStyle}" Visibility="{Binding Path=Visibility}" Source="{Binding Path=ImageUri}" ToolTip="{Binding Path=ToolTip}" /></Border>There is a Border control named borMain and a single Image control in this user control. That is all that is needed to display the buttons shown in Figure 1. The definition for this user control is in a DLL named PDSA.WPF. The Style definitions for both the Border and the Image controls are contained in a resource dictionary names PDSAButtonStyles.xaml. Using a resource dictionary allows you to create a few different resource dictionaries, each with a different theme for the buttons.The Visual State ManagerTo display the highlight around the button as your mouse moves over the control, you will need to add a Visual State Manager group. Two different states are needed; MouseEnter and MouseLeave. In the MouseEnter you create a ColorAnimation to modify the BorderBrush color of the Border control. You specify the color to animate as “DarkGray”. You set the duration to less than a second. The TargetName of this storyboard is the name of the Border control “borMain” and since we are specifying a single color, you need to set the TargetProperty to “BorderBrush.Color”. You do not need any storyboard for the MouseLeave state. Leaving this VisualState empty tells the Visual State Manager to put everything back the way it was before the MouseEnter event.<VisualStateManager.VisualStateGroups> <VisualStateGroup Name="MouseStates"> <VisualState Name="MouseEnter"> <Storyboard> <ColorAnimation To="DarkGray" Duration="0:0:00.1" Storyboard.TargetName="borMain" Storyboard.TargetProperty="BorderBrush.Color" /> </Storyboard> </VisualState> <VisualState Name="MouseLeave" /> </VisualStateGroup></VisualStateManager.VisualStateGroups>Writing the Mouse EventsTo trigger the Visual State Manager to run its storyboard in response to the specified event, you need to respond to the MouseEnter event on the Border control. In the code behind for this event call the GoToElementState() method of the VisualStateManager class exposed by the user control. To this method you will pass in the target element (“borMain”) and the state (“MouseEnter”). The VisualStateManager will then run the storyboard contained within the defined state in the XAML.private void borMain_MouseEnter(object sender, MouseEventArgs e){ VisualStateManager.GoToElementState(borMain, "MouseEnter", true);}You also need to respond to the MouseLeave event. In this event you call the VisualStateManager as well, but specify “MouseLeave” as the state to go to.private void borMain_MouseLeave(object sender, MouseEventArgs e){ VisualStateManager.GoToElementState(borMain, "MouseLeave", true);}The Resource DictionaryBelow is the definition of the PDSAButtonStyles.xaml resource dictionary file contained in the PDSA.WPF DLL. This dictionary can be used as the default look and feel for any image button control you add to a window. <ResourceDictionary ... >     <Style TargetType="Border" x:Key="pdsaButtonImageBorderStyle"> <Setter Property="Margin" Value="4" /> <Setter Property="Padding" Value="2" /> <Setter Property="BorderBrush" Value="Transparent" /> <Setter Property="BorderThickness" Value="1" /> <Setter Property="VerticalAlignment" Value="Top" /> <Setter Property="HorizontalAlignment" Value="Left" /> <Setter Property="Background" Value="Transparent" /> </Style>  <Style TargetType="Image" x:Key="pdsaButtonImageImageStyle"> <Setter Property="Width" Value="40" /> <Setter Property="Margin" Value="6" /> <Setter Property="VerticalAlignment" Value="Top" /> <Setter Property="HorizontalAlignment" Value="Left" /> </Style></ResourceDictionary>Using the Button ControlOnce you make a reference to the PDSA.WPF DLL from your WPF application you will see the “PDSAucButtonImage” control appear in your Toolbox. Drag and drop the button onto a Window or User Control in your application. I have not referenced the PDSAButtonStyles.xaml file within the control itself so you do need to add a reference to this resource dictionary somewhere in your application such as in the App.xaml.<Application.Resources> <ResourceDictionary> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="/PDSA.WPF;component/PDSAButtonStyles.xaml" /> </ResourceDictionary.MergedDictionaries> </ResourceDictionary></Application.Resources>This will give your buttons a default look and feel unless you override that dictionary on a specific Window or User Control or on an individual button. After you have given a global style to your application and you drag your image button onto a window, the following will appear in your XAML window.<my:PDSAucButtonImage ... />There will be some other attributes set on the above XAML, but you simply need to set the x:Name, the ToolTip and ImageUri properties. You will also want to respond to the Click event procedure in order to associate an action with clicking on this button. In the sample code you download for this blog post you will find the declaration of the Minimize button to be the following:<my:PDSAucButtonImage x:Name="btnMinimize" Click="btnMinimize_Click" ToolTip="Minimize Application" ImageUri="/PDSA.WPF;component/Images/Minus.png" />The ImageUri property is a dependency property in the PDSAucButtonImage user control. The x:Name and the ToolTip we get for free. You have to create the Click event procedure yourself. This is also created in the PDSAucButtonImage user control as follows:private void borMain_MouseLeftButtonDown(object sender, MouseButtonEventArgs e){ RaiseClick(e);}public delegate void ClickEventHandler(object sender, RoutedEventArgs e);public event ClickEventHandler Click;protected void RaiseClick(RoutedEventArgs e){ if (null != Click) Click(this, e);}Since a Border control does not have a Click event you will create one by using the MouseLeftButtonDown on the border to fire an event you create called “Click”.SummaryCreating your own image button control can be done in a variety of ways. In this blog post I showed you how to create a custom user control and simulate a button using a Border and Image control. With just a little bit of code to respond to the MouseLeftButtonDown event on the border you can raise your own Click event. Dependency properties, such as ImageUri, allow you to set attributes on your custom user control. Feel free to expand on this button by adding additional dependency properties, change the resource dictionary, and even the animation to make this button look and act like you want.NOTE: You can download the sample code for this article by visiting my website at http://www.pdsa.com/downloads. Select “Tips & Tricks”, then select “A WPF Image Button” from the drop down list.

Read the article

As a C# developer, would you learn Java to develop for Android or use MonoDroid instead?

- by Dan Tao

I'd consider myself pretty well versed in C#. It's my language of choice at the moment, and it's where basically all my professional experience lies. Still, I'm puzzled by the existence of the MonoDroid project. My understanding has always been that C# and Java are very close. Like, if you know one, you can learn the other really quickly. So, as I've considered developing my first Android app, I just assumed I would familiarize myself with Java enough to get started and then just sort of learn as I go. Wouldn't this make more sense than using MonoDroid, which is likely to be less feature-rich than the Java Android SDK, and requires learning its own API (albeit a .NET API) anyway? I just feel like it would be better to learn a new language (and an extremely popular one at that) and get some experience in it—when it's so close to what you already know anyway—rather than stick with a technology you're experienced with, without gaining any more valuable skills. Maybe I'm grossly misrepresenting the average potential MonoDroid user. Maybe it's more for people who are experienced in Java and .NET and just prefer .NET. Or maybe (in fact it's likely) there are other factors I just haven't considered. I'm just wondering, why would you use MonoDroid instead of just developing for Android using Java?

Read the article

What are some of the benefits of a "Micro-ORM"?

- by Wayne M

I've been looking into the so-called "Micro ORMs" like Dapper and (to a lesser extent as it relies on .NET 4.0) Massive as these might be easier to implement at work than a full-blown ORM since our current system is highly reliant on stored procedures and would require significant refactoring to work with an ORM like NHibernate or EF. What is the benefit of using one of these over a full-featured ORM? It seems like just a thin layer around a database connection that still forces you to write raw SQL - perhaps I'm wrong but I was always told the reason for ORMs in the first place is so you didn't have to write SQL, it could be automatically generated; especially for multi-table joins and mapping relationships between tables which are a pain to do in pure SQL but trivial with an ORM. For instance, looking at an example of Dapper: var connection = new SqlConnection(); // setup here... var person = connection.Query<Person>("select * from people where PersonId = @personId", new { PersonId = 42 }); How is that any different than using a handrolled ADO.NET data layer, except that you don't have to write the command, set the parameters and I suppose map the entity back using a Builder. It looks like you could even use a stored procedure call as the SQL string. Are there other tangible benefits that I'm missing here where a Micro ORM makes sense to use? I'm not really seeing how it's saving anything over the "old" way of using ADO.NET except maybe a few lines of code - you still have to write to figure out what SQL you need to execute (which can get hairy) and you still have to map relationships between tables (the part that IMHO ORMs help the most with).

Read the article

Clustering and custom applications

- by Ahmed ilyas

I was not entirely sure what tags to put but hope this is ok. This is just a general question in regards to clustering and applications: so lets say we have a clustered environment setup. We cluster SQL Server (I dont know exactly how its done but lets just say its been done for the sake of argument). Now if a website or application is trying to access that database for read/write (say an ASP.NET app or a C# Winforms app) and during that time SQL goes down - it takes a couple of minutes for the clustering failover to take affect to switch to another node. What happens during this time? I think it will time out/unable to connect. BUT is there a way for it to place the request in some pipeline so when the cluster node is back up/switched over it will continue as normal? as you can see, I know nothing much about clustering! what about your own custom .NET apps? Would there be a special way to develop them? I know that you can say create a simple Hello world app, and cluster that but they wouldnt be something you could see interms of the UI or anything, so they would effectively need to be developed as a Windows Service perhaps or even as a standard Console app which runs and not wait for user input but you wouldnt see any output from it (unless you redirect output to somewhere else) What im getting at here is... for those who have experience or developed a cluster application in .NET, how did you do it and what are the things to be aware of? For example we have the cloud service - fundamentally its built on clustering - if there is an outage, another node takes place and service is resumed as normal but we dont really see much of that downtime.

Read the article

Designing a system with different business rules for different customers

- by user1595846

My company is rewriting our proprietary business application. The current architecture is poorly done and inflexible. It is coded more procedural oriented as opposed to object oriented. It has become difficult to maintain. Our system is a web application written in .Net Webforms. I am considering ASP.Net MVC for the rewrite. We intend to rewrite it with a good, solid architecture with the goal of maintainability and reusable classes for some of our other systems and services. We would also like the system to be customizable for different customers in the event that we market the system. I am considering redesigning the system based on the layered architecture (Presentation, Business, Data Access layers) described in the Microsoft Patterns and Practices Application Architecture Guide. http://msdn.microsoft.com/en-us/library/ff650706.aspx Hopefully this isn't too open ended, but how would you recommend allowing for different business logic/rules for different customers? I'm aware of Windows Workflow Foundation, but from what I've read about it, it seems many business rules could be too complicated to handle there. Also, Can anyone point me to where I can download an example of a .net solution that is based on the Application Architecture Guide? I have already downloaded the Layered Architecture Solution Guidance and the Expense Sample on codeplex. I was looking for something a bit larger and more robust that I could step through the code and see how it works. If you feel there are better architectures to base our redesign on please feel free to share. I appreciate your help!

Read the article

Is there a massive other side to software development which I've somehow missed, revolving entirely around Microsoft?

- by Aerovistae

I'm still a beginning programmer; I've been at it for 2 years. I've learned to work with a few languages, a bit of web development technologies, a handful of libraries, frameworks, and IDEs. But over the past two years (and long before I even started, really), I keep hearing references to these...things. A million of them. Things such as C#, ADO, SOAP, ASP, ASP.NET, the .NET framework, CLR, F#, etc etc. And I've read their Wikipedia articles, in-depth, multiple times, and they all mention a million other things on that list, but I just can't seem to grasp what it all is. The only thing I've taken away with any certainty is that Microsoft is behind all of it. It sounds almost like a conspiracy. Are all these technologies just for developing on the Windows platform? What is .NET? Do some software developers dedicate their entire career just to that side of things? Why would I want to get into it, and what advantage does...whatever it is...have over all the other technologies there are? I hope this makes sense. It's a broad question, but inside it there's a very specific question asking about something I don't know the name of. Hopefully you can grasp my confusion.

Read the article

What exactly is bootstrap admin-template and how it is supposed to be used

- by Leron

So this is my second ASP.NET MVC 4 project. It's decided that for this one we will use this template and it was said in a way that I felt really stupid for not knowing how exactly this template will help us and what exactly we gain by using it. I'm used to using HTML/CSS for the UI combined with jQuery. Now it seems that instead of jQuery we will be using bootstrap which as far as I understand is just another JS library created from twitter, so if that's it then this part is clear. What I really need to clarify for myself is what exactly this theme is used for, what is offering, why one would want to use such a theme? From what I see in the live demo maybe it's just a stack of premade controls that you can use in the front end along with bootstrap.js and maybe I'm just confused because on the page is shown as much as possible just for presentational purposes. If that's right, still I wonder where I can find info for the current theme, the controls that it offers and the functionality that I get and not least - how to use it. But still those are just my assumptions. What I really need is a clarification on what exactly is this theme for, what is the advantage using it, is there a good tutorials about how to use such themes in the context of ASP.NET MVC 3+. Also any additional info about this theme and generally on using themes in ASP.NET MVC will be much appreciated.

Read the article

Persisting high score table in flash game without a network. (Featuring: HttpListenerException)

- by bearcdp

Hi everyone, this question is very programming-centric, but it's for a game so I figured I might as well post it here. I'm doing polishing work on a GGJ '11 game because it will be shown at an indie arcade tomorrow afternoon, and they're expecting our final build in the morning. We'd like to have a high score table that displays during attract mode, but since it's Flash (Flixel) it would require some networking, Mochi, or something to keep a record of these scores. Only problem is the machine we'd be running on probably won't have network access. As a quick solution, I thought I'd just write up a dinky little high score server in C#/.NET that could take basic GET requests for submitting scores and getting the score list. We're talking REAL basic, like blocking while waiting for an incoming request, run & forget console app, etc. There's no guarantee that our .swf won't get reloaded, and we'd like the scores to persist, so this server would pretty much exists to keep a safe copy of the scores that the game can add to and request, and occasionally the server will write the scores to a flat text file. But, HttpListener is giving me Error Code 87 'The parameter is incorrect.' Have any idea what I'm doing wrong? Or better yet, am I barking up the wrong tree and missing an obviously simpler solution? This is all I've got so far in my Main(): HttpListener listener = new HttpListener(); listener.Prefixes.Add("http://localhost:66666/"); listener.Start(); The exception happens at listener.Start(); and the stack trace is: at System.Net.HttpListener.AddAllPrefixes() at System.Net.HttpListener.Start() at WOSEBCE_ScoreServer.Program.Main(String[] args) in C:\Users\Michael\Documents\Visual Studio 2010\VS2010 Projects\WOSEBCE_ScoreServer\WOSEBCE_ScoreServer\Program.cs:line 24 at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart()

Read the article

IIS7Register failed with HRESULT 800700b7: 'Cannot create a file when that file already exists.'

- by Optimax

I am trying to re-install ASP.NET on IIS7 running in Win7/64, which magically stopped working all of as sudden. When I run aspnet_regiis -i, I get an error message that says Finished installing ASP.NET (4.0.30319). Setup has detected some errors during the operation. For details, please read the setup log file C:\Users\username\AppData\Local\Temp\ASPNETSetup_00031.log Looking at the log, it reports Failure Changing IIS ApplicationHost.config: IIS7Register failed with HRESULT 800700b7: 'Cannot create a file when that file already exists. ' The real problem surfaces when trying to access an ASP.NET web page from that server: HTTP Error 500.21 - Internal Server Error Handler "PageHandlerFactory-Integrated" has a bad module "ManagedPipelineHandler" in its module list and Most likely causes: Managed handler is used; however, ASP.NET is not installed or is not installed completely. There is a typographical error in the configuration for the handler module list. So it seems ASP.NET has NOT been properly re-installed. Now, I am aware of the alleged one-and-only remedy for this, repeated all over the Web, and referenced for example here: http://blogs.msdn.com/b/dougste/archive/2010/09/06/errors-installing-asp-net-4-0.aspx Except that the proposed solution does not work for me. I have expanded the %windir% macros within isapiCgiRestriction section for .NET 4.0 - and aspnet_regiis still fails for me. Any other ideas?

Read the article

How do you install .net4 on a Server 2008 r2 machine through psremoting in powershell?

- by Jake

I need to write a script that installs .net 4 remotely using powershell to a group of Server 2008 R2 machines. I based my script off of http://social.technet.microsoft.com/Forums/en-US/winserverpowershell/thread/3045eb24-7739-4695-ae94-5aa7052119fd/. enter-pssession -computername localhost $arglist = "/q /norestart /log C:\Users\tempuser\Desktop\dotnetfx4" $filepath = "C:\Users\tempuser\Desktop\dotNetFx40_Full_setup.exe" Start-Process -FilePath $filepath -ArgumentList $arglist -Wait -PassThru After running the command I would get the following log errors (running the same lines locally would install .net without error): Action: Downloading Item Failed to CreateJob : hr= 0x80200014 Action: Performing actions on all Items Action: Performing Action on Exe at C:\Users\tempuser\Desktop\dotnetfx4\SetupUtility.exe Exe (C:\Users\tempuser\Desktop\dotnetfx4\SetupUtility.exe) succeeded. Exe Log File: dd_SetupUtility.txt Action complete Action: ServiceControl - Stop clr_optimization_v2.0.50727_32 ServiceControl operation succeeded! Action complete Action: ServiceControl - Stop clr_optimization_v2.0.50727_64 ServiceControl operation succeeded! Action complete Action: Performing Action on Exe at C:\Users\tempuser\AppData\Local\Temp\Microsoft .NET Framework 4 Setup_4.0.30319\Windows6.1-KB958488-v6001-x64.msu Exe (C:\Users\tempuser\AppData\Local\Temp\Microsoft .NET Framework 4 Setup_4.0.30319\Windows6.1-KB958488-v6001-x64.msu) failed with 0x5 - Access is denied. . PerformOperation on exe returned exit code 5 (translates to HRESULT = 0x5) Action complete OnFailureBehavior for this item is to Rollback. Action: Performing actions on all Items Action complete Action complete Action: Downloading http://go.microsoft.com/fwlink/?LinkId=164184&clcid=0x409 using WinHttp WinHttpDetectAutoProxyConfigUrl failed with error: 12180 Unable to retrieve Proxy information although WinHttpGetIEProxyConfigForCurrentUser called succeeded Action complete C:\Users\tempuser\AppData\Local\Temp\Microsoft .NET Framework 4 Setup_4.0.30319\TMPF279.tmp.exe: Verifying signature for netfx_Core.mzz C:\Users\tempuser\AppData\Local\Temp\Microsoft .NET Framework 4 Setup_4.0.30319\TMPF279.tmp.exe Signature verified successfully for netfx_Core.mzz Action complete Decompression completed with code: 16389 Decompression of payload failed: C:\Users\tempuser\AppData\Local\Temp\Microsoft .NET Framework 4 Setup_4.0.30319\netfx_Core.mzz Action complete Final Result: Installation failed with error code: (0x80074005) (Elapsed time: 0 00:00:28). Is there some security setting or perhaps something else I've missed?

Read the article

netsnmp - how to register string?

- by user1495181

I use net-snmp. I try to add my own mibs (no need in handler, just a MIB that i can get and set by snmp call), so i followed the scalar example. In order to add my own mibs i defined them in the mib file and create an agent extension.(see below). It work, so i have now an integer MIB. Now i want to add string mib, so i define the MIB , but i dont find a register API for string, like i have for the int - netsnmp_register_int_instance. I look in the includes file , but dosnt found matching one. agent: #include <net-snmp/net-snmp-config.h> #include <net-snmp/net-snmp-includes.h> #include <net-snmp/agent/net-snmp-agent-includes.h> #include "monitor.h" static int int_init = 0; /* default value */ void init_monitor(void) { oid open_connections_count_oid[] = { 1, 3, 6, 1, 4, 1, 8075, 1, 0 }; netsnmp_register_int_instance("open_connections_count", open_connections_count_oid, OID_LENGTH(open_connections_count_oid), &int_init, NULL); }

Read the article

Why won't IIS serve my website? - 404 Page Not Found

- by Giffyguy

Built a brand new server, with a fresh copy of Windows Server 2003 Enterprise x86 Edition. Installed the .NET Framework 1.1, 2.0, 3.5, and 4.0 Added the "Domain Controller" and "Application Server" roles. Created a new website, pointed it to a local directory: C:\Inetpub\angryoctopus.net\ Added the appropriate headers: angryoctopus.net, www.angryoctopus.net, TCP port 80, all IPs Moved the website content into the local directory. Configured the default document in IIS: Default.aspx Enabled ASP.NET for this website, and set it to the correct version: 2.0.50727 Configured the zone angryoctopus.net in DNS. Tested DNS lookup here to ensure DNS was functional. Opened website in VS 2008 and re-built (and debugged) to ensure the content was functional. I can clearly see that IIS is responding normally, by browsing directly to my server's IP address. Since this does not use the angryoctopus HTTP header, the default website is displayed instead: the "Under Construction" page. And yet, after all of this, angryoctopus.net still returns 404. Does anybody know what could be wrong? What troubleshooting steps have I forgotten? Is there a command-line diagnostic that might provide more information?

Read the article

How do I use C# and ADO.NET to query an Oracle table with a spatial column of type SDO_GEOMETRY?

- by John Donahue

My development machine is running Windows 7 Enterprise, 64-bit version. I am using Visual Studio 2010 Release Candidate. I am connecting to an Oracle 11g Enterprise server version 11.1.0.7.0. I had a difficult time locating Oracle client software that is made for 64-bit Windows systems and eventually landed here to download what I assume is the proper client connectivity software. I added a reference to "Oracle.DataAccess" which is version 2.111.6.0 (Runtime Version is v2.0.50727). I am targeting .NET CLR version 4.0 since all properties of my VS Solution are defaults and this is 2010 RC. I was then able to write a console application in C# that established connectivity, executed a SELECT statement, and properly returned data when the table in question does NOT contain a spatial column. My problem is that this no longer works when the table I query has a column of type SDO_GEOMETRY in it. Below is the simple console application I am trying to run that reproduces the problem. When the code gets to the line with the "ExecuteReader" command, an exception is raised and the message is "Unsupported column datatype". using System; using System.Data; using Oracle.DataAccess.Client; namespace ConsoleTestOracle { class Program { static void Main(string[] args) { string oradb = string.Format("Data Source={0};User Id={1};Password={2};", "hostname/servicename", "login", "password"); try { using (OracleConnection conn = new OracleConnection(oradb)) { conn.Open(); OracleCommand cmd = new OracleCommand(); cmd.Connection = conn; cmd.CommandText = "select * from SDO_8307_2D_POINTS"; cmd.CommandType = CommandType.Text; OracleDataReader dr = cmd.ExecuteReader(); } } catch (Exception e) { string error = e.Message; } } } } The fact that this code works when used against a table that does not contain a spatial column of type SDO_GEOMETRY makes me think I have my windows 7 machine properly configured so I am surprised that I get this exception when the table contains different kinds of columns. I don't know if there is some configuration on my machine or the Oracle machine that needs to be done, or if the Oracle client software I have installed is wrong, or old and needs to be updated. Here is the SQL I used to create the table, populate it with some rows containing points in the spatial column, etc. if you want to try to reproduce this exactly. SQL Create Commands: create table SDO_8307_2D_Points (ObjectID number(38) not null unique, TestID number, shape SDO_GEOMETRY); Insert into SDO_8307_2D_Points values (1, 1, SDO_GEOMETRY(2001, 8307, null, SDO_ELEM_INFO_ARRAY(1, 1, 1), SDO_ORDINATE_ARRAY(10.0, 10.0))); Insert into SDO_8307_2D_Points values (2, 2, SDO_GEOMETRY(2001, 8307, null, SDO_ELEM_INFO_ARRAY(1, 1, 1), SDO_ORDINATE_ARRAY(10.0, 20.0))); insert into user_sdo_geom_metadata values ('SDO_8307_2D_Points', 'SHAPE', SDO_DIM_ARRAY(SDO_DIM_ELEMENT('Lat', -180, 180, 0.05), SDO_DIM_ELEMENT('Long', -90, 90, 0.05)), 8307); create index SDO_8307_2D_Point_indx on SDO_8307_2D_Points(shape) indextype is mdsys.spatial_index PARAMETERS ('sdo_indx_dims=2' ); Any advice or insights would be greatly appreciated. Thank you.

Read the article

Java web-app debugging not possible due to direct undeploy on debug

- by Hendrik

When i try to debug my webapp it starts up the tomcat server and the application, but shuts down the debugger shortly before the app gets usable. I see the debugging toolbar for a second before it vanishes again, though the app keeps running. Tomcat-log: Listening for transport dt_socket at address: 11555 23.03.2010 01:24:35 org.apache.catalina.core.AprLifecycleListener init INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: .:/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java 23.03.2010 01:24:35 org.apache.coyote.http11.Http11Protocol init INFO: Initializing Coyote HTTP/1.1 on http-8084 23.03.2010 01:24:35 org.apache.catalina.startup.Catalina load INFO: Initialization processed in 847 ms 23.03.2010 01:24:35 org.apache.catalina.core.StandardService start INFO: Starting service Catalina 23.03.2010 01:24:35 org.apache.catalina.core.StandardEngine start INFO: Starting Servlet Engine: Apache Tomcat/6.0.20 log4j:WARN No appenders could be found for logger (org.springframework.web.context.ContextLoader). log4j:WARN Please initialize the log4j system properly. 23.03.2010 01:24:41 org.apache.coyote.http11.Http11Protocol start INFO: Starting Coyote HTTP/1.1 on http-8084 23.03.2010 01:24:41 org.apache.jk.common.ChannelSocket init INFO: JK: ajp13 listening on /0.0.0.0:8009 23.03.2010 01:24:41 org.apache.jk.server.JkMain start INFO: Jk running ID=0 time=0/78 config=null 23.03.2010 01:24:41 org.apache.catalina.startup.Catalina start INFO: Server startup in 5855 ms 23.03.2010 01:24:42 org.apache.catalina.startup.HostConfig checkResources INFO: Undeploying context [] 23.03.2010 01:24:45 org.apache.catalina.core.StandardContext start INFO: Container org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/] has already been started Debugging log: Attached JPDA debugger to localhost:11555 Checking data source definitions for missing JDBC drivers... Deploying JDBC driver to /Applications/NetBeans/apache-tomcat-6.0.20/lib/mysql-connector-java-5.1.6-bin.jar Stopping Tomcat process... Waiting for Tomcat... Tomcat server stopped. Starting Tomcat process... Waiting for Tomcat... Tomcat server started. Undeploying ... OK - Undeployed application at context path / In-place deployment at /path/to/project/dir/build/web deploy?config=file%3A%2Fvar%2Ffolders%2FZP%2FZPbqxGrbHFaUlXzAfgWV1%2B%2B%2B%2BTQ%2F-Tmp-%2Fcontext734173871283203218.xml&path=/ OK - Deployed application at context path / start?path=/ Start is in progress... OK - Started application at context path / debug-display-browser: Browsing: http://localhost:8084/ connect-client-debugger: BUILD SUCCESSFUL (total time: 18 seconds) System is Netbeans 6.8 on MacOS 10.6.2. Thank you very much, guys!

Read the article

Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 3 – Table per Concrete Type (TPC) and Choosing Strategy Guidelines

- by mortezam

This is the third (and last) post in a series that explains different approaches to map an inheritance hierarchy with EF Code First. I've described these strategies in previous posts: Part 1 – Table per Hierarchy (TPH) Part 2 – Table per Type (TPT)In today’s blog post I am going to discuss Table per Concrete Type (TPC) which completes the inheritance mapping strategies supported by EF Code First. At the end of this post I will provide some guidelines to choose an inheritance strategy mainly based on what we've learned in this series. TPC and Entity Framework in the Past Table per Concrete type is somehow the simplest approach suggested, yet using TPC with EF is one of those concepts that has not been covered very well so far and I've seen in some resources that it was even discouraged. The reason for that is just because Entity Data Model Designer in VS2010 doesn't support TPC (even though the EF runtime does). That basically means if you are following EF's Database-First or Model-First approaches then configuring TPC requires manually writing XML in the EDMX file which is not considered to be a fun practice. Well, no more. You'll see that with Code First, creating TPC is perfectly possible with fluent API just like other strategies and you don't need to avoid TPC due to the lack of designer support as you would probably do in other EF approaches. Table per Concrete Type (TPC)In Table per Concrete type (aka Table per Concrete class) we use exactly one table for each (nonabstract) class. All properties of a class, including inherited properties, can be mapped to columns of this table, as shown in the following figure: As you can see, the SQL schema is not aware of the inheritance; effectively, we’ve mapped two unrelated tables to a more expressive class structure. If the base class was concrete, then an additional table would be needed to hold instances of that class. I have to emphasize that there is no relationship between the database tables, except for the fact that they share some similar columns. TPC Implementation in Code First Just like the TPT implementation, we need to specify a separate table for each of the subclasses. We also need to tell Code First that we want all of the inherited properties to be mapped as part of this table. In CTP5, there is a new helper method on EntityMappingConfiguration class called MapInheritedProperties that exactly does this for us. Here is the complete object model as well as the fluent API to create a TPC mapping: public abstract class BillingDetail { public int BillingDetailId { get; set; } public string Owner { get; set; } public string Number { get; set; } } public class BankAccount : BillingDetail { public string BankName { get; set; } public string Swift { get; set; } } public class CreditCard : BillingDetail { public int CardType { get; set; } public string ExpiryMonth { get; set; } public string ExpiryYear { get; set; } } public class InheritanceMappingContext : DbContext { public DbSet<BillingDetail> BillingDetails { get; set; } protected override void OnModelCreating(ModelBuilder modelBuilder) { modelBuilder.Entity<BankAccount>().Map(m => { m.MapInheritedProperties(); m.ToTable("BankAccounts"); }); modelBuilder.Entity<CreditCard>().Map(m => { m.MapInheritedProperties(); m.ToTable("CreditCards"); }); } } The Importance of EntityMappingConfiguration ClassAs a side note, it worth mentioning that EntityMappingConfiguration class turns out to be a key type for inheritance mapping in Code First. Here is an snapshot of this class: namespace System.Data.Entity.ModelConfiguration.Configuration.Mapping { public class EntityMappingConfiguration<TEntityType> where TEntityType : class { public ValueConditionConfiguration Requires(string discriminator); public void ToTable(string tableName); public void MapInheritedProperties(); } } As you have seen so far, we used its Requires method to customize TPH. We also used its ToTable method to create a TPT and now we are using its MapInheritedProperties along with ToTable method to create our TPC mapping. TPC Configuration is Not Done Yet!We are not quite done with our TPC configuration and there is more into this story even though the fluent API we saw perfectly created a TPC mapping for us in the database. To see why, let's start working with our object model. For example, the following code creates two new objects of BankAccount and CreditCard types and tries to add them to the database: using (var context = new InheritanceMappingContext()) { BankAccount bankAccount = new BankAccount(); CreditCard creditCard = new CreditCard() { CardType = 1 }; context.BillingDetails.Add(bankAccount); context.BillingDetails.Add(creditCard); context.SaveChanges(); } Running this code throws an InvalidOperationException with this message: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges. The reason we got this exception is because DbContext.SaveChanges() internally invokes SaveChanges method of its internal ObjectContext. ObjectContext's SaveChanges method on its turn by default calls AcceptAllChanges after it has performed the database modifications. AcceptAllChanges method merely iterates over all entries in ObjectStateManager and invokes AcceptChanges on each of them. Since the entities are in Added state, AcceptChanges method replaces their temporary EntityKey with a regular EntityKey based on the primary key values (i.e. BillingDetailId) that come back from the database and that's where the problem occurs since both the entities have been assigned the same value for their primary key by the database (i.e. on both BillingDetailId = 1) and the problem is that ObjectStateManager cannot track objects of the same type (i.e. BillingDetail) with the same EntityKey value hence it throws. If you take a closer look at the TPC's SQL schema above, you'll see why the database generated the same values for the primary keys: the BillingDetailId column in both BankAccounts and CreditCards table has been marked as identity. How to Solve The Identity Problem in TPC As you saw, using SQL Server’s int identity columns doesn't work very well together with TPC since there will be duplicate entity keys when inserting in subclasses tables with all having the same identity seed. Therefore, to solve this, either a spread seed (where each table has its own initial seed value) will be needed, or a mechanism other than SQL Server’s int identity should be used. Some other RDBMSes have other mechanisms allowing a sequence (identity) to be shared by multiple tables, and something similar can be achieved with GUID keys in SQL Server. While using GUID keys, or int identity keys with different starting seeds will solve the problem but yet another solution would be to completely switch off identity on the primary key property. As a result, we need to take the responsibility of providing unique keys when inserting records to the database. We will go with this solution since it works regardless of which database engine is used. Switching Off Identity in Code First We can switch off identity simply by placing DatabaseGenerated attribute on the primary key property and pass DatabaseGenerationOption.None to its constructor. DatabaseGenerated attribute is a new data annotation which has been added to System.ComponentModel.DataAnnotations namespace in CTP5: public abstract class BillingDetail { [DatabaseGenerated(DatabaseGenerationOption.None)] public int BillingDetailId { get; set; } public string Owner { get; set; } public string Number { get; set; } } As always, we can achieve the same result by using fluent API, if you prefer that: modelBuilder.Entity<BillingDetail>() .Property(p => p.BillingDetailId) .HasDatabaseGenerationOption(DatabaseGenerationOption.None); Working With The Object Model Our TPC mapping is ready and we can try adding new records to the database. But, like I said, now we need to take care of providing unique keys when creating new objects: using (var context = new InheritanceMappingContext()) { BankAccount bankAccount = new BankAccount() { BillingDetailId = 1 }; CreditCard creditCard = new CreditCard() { BillingDetailId = 2, CardType = 1 }; context.BillingDetails.Add(bankAccount); context.BillingDetails.Add(creditCard); context.SaveChanges(); } Polymorphic Associations with TPC is Problematic The main problem with this approach is that it doesn’t support Polymorphic Associations very well. After all, in the database, associations are represented as foreign key relationships and in TPC, the subclasses are all mapped to different tables so a polymorphic association to their base class (abstract BillingDetail in our example) cannot be represented as a simple foreign key relationship. For example, consider the the domain model we introduced here where User has a polymorphic association with BillingDetail. This would be problematic in our TPC Schema, because if User has a many-to-one relationship with BillingDetail, the Users table would need a single foreign key column, which would have to refer both concrete subclass tables. This isn’t possible with regular foreign key constraints. Schema Evolution with TPC is Complex A further conceptual problem with this mapping strategy is that several different columns, of different tables, share exactly the same semantics. This makes schema evolution more complex. For example, a change to a base class property results in changes to multiple columns. It also makes it much more difficult to implement database integrity constraints that apply to all subclasses. Generated SQLLet's examine SQL output for polymorphic queries in TPC mapping. For example, consider this polymorphic query for all BillingDetails and the resulting SQL statements that being executed in the database: var query = from b in context.BillingDetails select b; Just like the SQL query generated by TPT mapping, the CASE statements that you see in the beginning of the query is merely to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type). TPC's SQL Queries are Union Based As you can see in the above screenshot, the first SELECT uses a FROM-clause subquery (which is selected with a red rectangle) to retrieve all instances of BillingDetails from all concrete class tables. The tables are combined with a UNION operator, and a literal (in this case, 0 and 1) is inserted into the intermediate result; (look at the lines highlighted in yellow.) EF reads this to instantiate the correct class given the data from a particular row. A union requires that the queries that are combined, project over the same columns; hence, EF has to pad and fill up nonexistent columns with NULL. This query will really perform well since here we can let the database optimizer find the best execution plan to combine rows from several tables. There is also no Joins involved so it has a better performance than the SQL queries generated by TPT where a Join is required between the base and subclasses tables. Choosing Strategy GuidelinesBefore we get into this discussion, I want to emphasize that there is no one single "best strategy fits all scenarios" exists. As you saw, each of the approaches have their own advantages and drawbacks. Here are some rules of thumb to identify the best strategy in a particular scenario: If you don’t require polymorphic associations or queries, lean toward TPC—in other words, if you never or rarely query for BillingDetails and you have no class that has an association to BillingDetail base class. I recommend TPC (only) for the top level of your class hierarchy, where polymorphism isn’t usually required, and when modification of the base class in the future is unlikely. If you do require polymorphic associations or queries, and subclasses declare relatively few properties (particularly if the main difference between subclasses is in their behavior), lean toward TPH. Your goal is to minimize the number of nullable columns and to convince yourself (and your DBA) that a denormalized schema won’t create problems in the long run. If you do require polymorphic associations or queries, and subclasses declare many properties (subclasses differ mainly by the data they hold), lean toward TPT. Or, depending on the width and depth of your inheritance hierarchy and the possible cost of joins versus unions, use TPC. By default, choose TPH only for simple problems. For more complex cases (or when you’re overruled by a data modeler insisting on the importance of nullability constraints and normalization), you should consider the TPT strategy. But at that point, ask yourself whether it may not be better to remodel inheritance as delegation in the object model (delegation is a way of making composition as powerful for reuse as inheritance). Complex inheritance is often best avoided for all sorts of reasons unrelated to persistence or ORM. EF acts as a buffer between the domain and relational models, but that doesn’t mean you can ignore persistence concerns when designing your classes. SummaryIn this series, we focused on one of the main structural aspect of the object/relational paradigm mismatch which is inheritance and discussed how EF solve this problem as an ORM solution. We learned about the three well-known inheritance mapping strategies and their implementations in EF Code First. Hopefully it gives you a better insight about the mapping of inheritance hierarchies as well as choosing the best strategy for your particular scenario. Happy New Year and Happy Code-Firsting! References ADO.NET team blog Java Persistence with Hibernate book a { color: #5A99FF; } a:visited { color: #5A99FF; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } .exception { background-color: #f0f0f0; font-style: italic; padding-bottom: 5px; padding-left: 5px; padding-top: 5px; padding-right: 5px; }

Read the article

jQuery Templates - {Supported Tags}

- by hajan

I have started with Introduction to jQuery Templates, then jQuery Templates - tmpl(), template() and tmplItem() functions. In this blog we will see what supported tags are available in the jQuery Templates plugin.Template tags can be used inside template together in combination with HTML tags and plain text, which helps to iterate over JSON data. Up to now, there are several supported tags in jQuery Templates plugin: ${expr} or {{= expr}} {{each itemArray}} … {{/each}} {{if condition}} … {{else}} … {{/if}} {{html …}} {{tmpl …}} {{wrap …}} … {{/wrap}} - ${expr} or {{= expr}} Is used for insertion of data values in the rendered template. It can evaluate fields, functions or expression. Example: <script id="attendeesTemplate" type="text/html"> <li> ${Name} {{= Surname}} </li> </script> Either ${Name} or {{= Surname}} (with blank space between =<blankspace>Field) will work. - {{each itemArray}} … {{/each}} each is everywhere the same "(for)each", used to loop over array or collection Example: <script id="attendeesTemplate" type="text/html"> <li> ${Name} ${Surname} {{if speaker}} (<font color="red">speaks</font>) {{else}} (attendee) {{/if}} {{each phones}} <br /> ${$index}: <em>${$value}</em> {{/each}} </li> </script> So, you see we can use ${$index} and ${$value} to get the current index and value while iterating over the item collection. Alternatively, you can add index,value on the following way: {{each(i,v) phones}} <br /> ${i}: <em>${v}</em> {{/each}} Result would be: Here is complete working example that you can run and see the result: <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> <title>Nesting and Looping Example :: jQuery Templates</title> <script src="http://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.4.4.min.js" type="text/javascript"></script> <script src="http://ajax.aspnetcdn.com/ajax/jquery.templates/beta1/jquery.tmpl.js" type="text/javascript"></script> <script language="javascript" type="text/javascript"> $(function () { var attendees = [ { Name: "Hajan", Surname: "Selmani", speaker: true, phones:[070555555, 071888999, 071222333] }, { Name: "Someone", Surname: "Surname", phones: [070555555, 071222333] }, { Name: "Third", Surname: "Thirdsurname", phones: [070555555, 071888999, 071222333] }, ]; $("#attendeesTemplate").tmpl(attendees).appendTo("#attendeesList"); }); </script> <script id="attendeesTemplate" type="text/html"> <li> ${Name} ${Surname} {{if speaker}} (<font color="red">speaks</font>) {{else}} (attendee) {{/if}} {{each(i,v) phones}} <br /> ${i}: <em>${v}</em> {{/each}} </li> </script> </head> <body> <ol id="attendeesList"></ol> </body> </html> - {{if condition}} … {{else}} … {{/if}} Standard if/else statement. Of course, you can use it without the {{else}} if you have such condition to check, however closing the {{/if}} tag is required. Example: {{if speaker}} (<font color="red">speaks</font>) {{else}} (attendee) {{/if}} You have this same code block in the above complete example showing the 'each' cycle ;). - {{html …}} Is used for insertion of HTML markup strings in the rendered template. Evaluates the specified field on the current data item, or the specified JavaScript function or expression. Example: - without {{html …}} <script language="javascript" type="text/javascript"> $(function () { var attendees = [ { Name: "Hajan", Surname: "Selmani", Info: "He <font color='red'>is the speaker of today's</font> session", speaker: true }, ]; $("#myTemplate").tmpl(attendees).appendTo("#speakers"); }); </script> <script id="myTemplate" type="text/html"> ${Name} ${Surname} <br /> ${Info} </script> Result: - with {{html …}} <script language="javascript" type="text/javascript"> $(function () { var attendees = [ { Name: "Hajan", Surname: "Selmani", Info: "He <font color='red'>is the speaker of today's</font> session", speaker: true }, ]; $("#myTemplate").tmpl(attendees).appendTo("#speakers"); }); </script> <script id="myTemplate" type="text/html"> ${Name} ${Surname} <br /> {{html Info}} </script> Result: - {{wrap …}} It’s used for composition and incorporation of wrapped HTML. It’s similar to {{tmpl}} Example: <script id="myTmpl" type="text/html"> <div id="personInfo"> <br /> ${Name} ${Surname} {{wrap "#myWrapper"}} <h2>${Info}</h2> <div> {{if speaker}} (speaker) {{else}} (attendee) {{/if}} </div> {{/wrap}} </div> </script> <script id="myWrapper" type="text/html"> <table><tbody> <tr> {{each $item.html("div")}} <td> {{html $value}} </td> {{/each}} </tr> </tbody></table> </script> All the HTMl content inside the {{wrap}} … {{/wrap}} is available to the $item.html(filter, textOnly) method. In our example, we have defined some standard template and created wrapper which calls the other template with id myWrapper. Then using $item.html(“div”) we find the div tag and render the html value (together with the div tag) inside the <td> … </td>. So, here inside td the <div> <speaker or attendee depending of the condition> </div> will be rendered. The HTML output from this is: - {{tmpl …}} Used for composition as template items Example: <script id="myTemplate" type="text/html"> <div id="bookItem"> <div id="bookCover"> {{tmpl "#bookCoverTemplate"}} </div> <div id="bookDetails"> <div id="book"> ${title} - ${author} </div> <div id="price">$${price}</div> <div id="Details">${pages} pgs. - ${year} year</div> </div> </div> </script> <script id="bookCoverTemplate" type="text/html"> <img src="${image}" alt="${title} Image" /> </script> In this example, using {{tmpl “#bookCoverTemplate”}} I’m calling another template inside the first template. In the other template I’ve created template for a book cover. The rendered HTML of this is: and So we have seen example for each of the tags that are right now available in the jQuery Templates (beta) plugin which is created by Microsoft as a contribution to the open source jQuery Project. I hope this was useful blog post for you. Regards, HajanNEXT - jQuery Templates with ASP.NET MVC

Read the article

Change the default Icon on your jQuery UI Accordion

- by hajan

I've got this question in one of my previous blogs posted here (the same blog is posted on codeasp.net too), dealing with jQuery UI Accordion and I thought it's nice to recap this in a blog post so that I will have it documented for further reference. In the previous blog, I'm creating tabs content navigation using jQuery UI Accordion. So, it's quite simple code and all I do there is calling accordion() function. <script language="javascript" type="text/javascript"> $(function() { $("#products").accordion(); }); </script> The default image icons for each item is the arrow. The accordion uses the right arrow and down arrow images. So, what we should do in order to change them? JQuery UI Accordion contains option with name icons that has header and headerSelected properties. We can override them with either the existing classes from jQuery UI themes or with our own. 1. Using existing jQuery UI Theme classes - Open the follownig link: http://jqueryui.com/themeroller/#icons You will see the icons available in the jQuery UI theme. Mouse over on each icon and you will see the class name for each icon. As you can see, each icon has class name constructed in the following way: ui-icon-<name> All icons in one image - In our example, I will use ui-icon-circle-plus and ui-icon-circle-minus (plus and minus icons). - Lets set the icons <script language="javascript" type="text/javascript"> $(function() { //initialize accordion $("#products").accordion(); //set accordion header options $("#products").accordion("option", "icons", { 'header': 'ui-icon-circle-plus', 'headerSelected': 'ui-icon-circle-minus' }); }); </script> From the code above, you can see that I first intialize the accordion plugin, and after I override the default icons with the ui-icon-circle-plyus for header and ui-icon-circle-minus for headerSelected. Here is the end result: So, now you see we have the plus/minus circle icons for the default header state and the selected header state. 2. Add my own icons - If you want to add your own icons, you can do that by creating your own custom css classes. - Lets create classes for both, the header default state and header selected state <style type="text/css"> .defaultIcon { background-image: url(images/icons/defaultIcon.png) !important; width: 25px; height: 25px; } .selectedIcon { background-image: url(images/icons/selectedIcon.png) !important; width: 25px; height: 25px; } </style> As you can see, I use my own images placed in images/icons/ folder - default icon - selected icon One very important thing to note here is the !important key added on each background-image property. It's like that in order to give highest importancy to our image so that the default jQuery UI theme icon images will have less importancy and won't be used. And the jQuery code is: <script language="javascript" type="text/javascript"> $(function() { //initialize accordion $("#products").accordion(); //set accordion header options $("#products").accordion("option", "icons", { 'header': 'defaultIcon', 'headerSelected': 'selectedIcon' }); }); </script> Note: For both #1 and #2 cases, we use the class names without adding . (dot) at the beginning of the name (as we do with selectors). That's because the the header and headerSelected properties accept classes only as a value, so the rest is done by the plugin itself. The complete code with my own custom images is: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head id="Head1" runat="server"> <title>jQuery Accordion</title> <link type="text/css" href="http://ajax.microsoft.com/ajax/jquery.ui/1.8.5/themes/blitzer/jquery-ui.css" rel="Stylesheet" /> <style type="text/css"> .defaultIcon { background-image: url(images/icons/defaultIcon.png) !important; width: 25px; height: 25px; } .selectedIcon { background-image: url(images/icons/selectedIcon.png) !important; width: 25px; height: 25px; } </style> <script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jquery/jquery-1.4.4.js"></script> <script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.6/jquery-ui.js"></script> <script language="javascript" type="text/javascript"> $(function() { //initialize accordion $("#products").accordion(); //set accordion header options $("#products").accordion("option", "icons", { 'header': 'defaultIcon', 'headerSelected': 'selectedIcon' }); }); </script> </head> <body> <form id="form1" runat="server"> <div id="products" style="width: 500px;"> <h3> <a href="#"> Product 1</a></h3> <div> <p> Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus in tortor metus, a aliquam dui. Mauris euismod lorem eget nulla semper semper. Vestibulum pretium rhoncus cursus. Vestibulum rhoncus, magna sit amet fermentum fringilla, nunc nisl pellentesque libero, nec commodo libero ipsum a tellus. Maecenas sed varius est. Sed vel risus at nisi imperdiet sollicitudin eget ac orci. Duis ac tristique sem. </p> </div> <h3> <a href="#"> Product 2</a></h3> <div> <p> Aliquam pretium scelerisque nisl in malesuada. Proin dictum elementum rutrum. Etiam eleifend massa id dui porta tincidunt. Integer sodales nisi nec ligula lacinia tincidunt vel in purus. Mauris ultrices velit quis massa dignissim rhoncus. Proin posuere convallis euismod. Vestibulum convallis sagittis arcu id faucibus. </p> </div> <h3> <a href="#"> Product 3</a></h3> <div> <p> Quisque quis magna id nibh laoreet condimentum a sed nisl. In hac habitasse platea dictumst. Proin sem eros, dignissim sed consequat sit amet, interdum id ante. Ut id nisi in ante fermentum accumsan vitae ut est. Morbi tellus enim, convallis ac rutrum a, condimentum ut turpis. Proin sit amet pretium felis. </p> <ul> <li>List item one</li> <li>List item two</li> <li>List item three</li> </ul> </div> </div> </form> </body> </html> The end result is: Hope this was helpful. Regards,Hajan

Read the article

A ToDynamic() Extension Method For Fluent Reflection

- by Dixin

Recently I needed to demonstrate some code with reflection, but I felt it inconvenient and tedious. To simplify the reflection coding, I created a ToDynamic() extension method. The source code can be downloaded from here. Problem One example for complex reflection is in LINQ to SQL. The DataContext class has a property Privider, and this Provider has an Execute() method, which executes the query expression and returns the result. Assume this Execute() needs to be invoked to query SQL Server database, then the following code will be expected: using (NorthwindDataContext database = new NorthwindDataContext()) { // Constructs the query. IQueryable<Product> query = database.Products.Where(product => product.ProductID > 0) .OrderBy(product => product.ProductName) .Take(2); // Executes the query. Here reflection is required, // because Provider, Execute(), and ReturnValue are not public members. IEnumerable<Product> results = database.Provider.Execute(query.Expression).ReturnValue; // Processes the results. foreach (Product product in results) { Console.WriteLine("{0}, {1}", product.ProductID, product.ProductName); } } Of course, this code cannot compile. And, no one wants to write code like this. Again, this is just an example of complex reflection. using (NorthwindDataContext database = new NorthwindDataContext()) { // Constructs the query. IQueryable<Product> query = database.Products.Where(product => product.ProductID > 0) .OrderBy(product => product.ProductName) .Take(2); // database.Provider PropertyInfo providerProperty = database.GetType().GetProperty( "Provider", BindingFlags.NonPublic | BindingFlags.GetProperty | BindingFlags.Instance); object provider = providerProperty.GetValue(database, null); // database.Provider.Execute(query.Expression) // Here GetMethod() cannot be directly used, // because Execute() is a explicitly implemented interface method. Assembly assembly = Assembly.Load("System.Data.Linq"); Type providerType = assembly.GetTypes().SingleOrDefault( type => type.FullName == "System.Data.Linq.Provider.IProvider"); InterfaceMapping mapping = provider.GetType().GetInterfaceMap(providerType); MethodInfo executeMethod = mapping.InterfaceMethods.Single(method => method.Name == "Execute"); IExecuteResult executeResult = executeMethod.Invoke(provider, new object[] { query.Expression }) as IExecuteResult; // database.Provider.Execute(query.Expression).ReturnValue IEnumerable<Product> results = executeResult.ReturnValue as IEnumerable<Product>; // Processes the results. foreach (Product product in results) { Console.WriteLine("{0}, {1}", product.ProductID, product.ProductName); } } This may be not straight forward enough. So here a solution will implement fluent reflection with a ToDynamic() extension method: IEnumerable<Product> results = database.ToDynamic() // Starts fluent reflection. .Provider.Execute(query.Expression).ReturnValue; C# 4.0 dynamic In this kind of scenarios, it is easy to have dynamic in mind, which enables developer to write whatever code after a dot: using (NorthwindDataContext database = new NorthwindDataContext()) { // Constructs the query. IQueryable<Product> query = database.Products.Where(product => product.ProductID > 0) .OrderBy(product => product.ProductName) .Take(2); // database.Provider dynamic dynamicDatabase = database; dynamic results = dynamicDatabase.Provider.Execute(query).ReturnValue; } This throws a RuntimeBinderException at runtime: 'System.Data.Linq.DataContext.Provider' is inaccessible due to its protection level. Here dynamic is able find the specified member. So the next thing is just writing some custom code to access the found member. .NET 4.0 DynamicObject, and DynamicWrapper<T> Where to put the custom code for dynamic? The answer is DynamicObject’s derived class. I first heard of DynamicObject from Anders Hejlsberg's video in PDC2008. It is very powerful, providing useful virtual methods to be overridden, like: TryGetMember() TrySetMember() TryInvokeMember() etc. (In 2008 they are called GetMember, SetMember, etc., with different signature.) For example, if dynamicDatabase is a DynamicObject, then the following code: dynamicDatabase.Provider will invoke dynamicDatabase.TryGetMember() to do the actual work, where custom code can be put into. Now create a type to inherit DynamicObject: public class DynamicWrapper<T> : DynamicObject { private readonly bool _isValueType; private readonly Type _type; private T _value; // Not readonly, for value type scenarios. public DynamicWrapper(ref T value) // Uses ref in case of value type. { if (value == null) { throw new ArgumentNullException("value"); } this._value = value; this._type = value.GetType(); this._isValueType = this._type.IsValueType; } public override bool TryGetMember(GetMemberBinder binder, out object result) { // Searches in current type's public and non-public properties. PropertyInfo property = this._type.GetTypeProperty(binder.Name); if (property != null) { result = property.GetValue(this._value, null).ToDynamic(); return true; } // Searches in explicitly implemented properties for interface. MethodInfo method = this._type.GetInterfaceMethod(string.Concat("get_", binder.Name), null); if (method != null) { result = method.Invoke(this._value, null).ToDynamic(); return true; } // Searches in current type's public and non-public fields. FieldInfo field = this._type.GetTypeField(binder.Name); if (field != null) { result = field.GetValue(this._value).ToDynamic(); return true; } // Searches in base type's public and non-public properties. property = this._type.GetBaseProperty(binder.Name); if (property != null) { result = property.GetValue(this._value, null).ToDynamic(); return true; } // Searches in base type's public and non-public fields. field = this._type.GetBaseField(binder.Name); if (field != null) { result = field.GetValue(this._value).ToDynamic(); return true; } // The specified member is not found. result = null; return false; } // Other overridden methods are not listed. } In the above code, GetTypeProperty(), GetInterfaceMethod(), GetTypeField(), GetBaseProperty(), and GetBaseField() are extension methods for Type class. For example: internal static class TypeExtensions { internal static FieldInfo GetBaseField(this Type type, string name) { Type @base = type.BaseType; if (@base == null) { return null; } return @base.GetTypeField(name) ?? @base.GetBaseField(name); } internal static PropertyInfo GetBaseProperty(this Type type, string name) { Type @base = type.BaseType; if (@base == null) { return null; } return @base.GetTypeProperty(name) ?? @base.GetBaseProperty(name); } internal static MethodInfo GetInterfaceMethod(this Type type, string name, params object[] args) { return type.GetInterfaces().Select(type.GetInterfaceMap).SelectMany(mapping => mapping.TargetMethods) .FirstOrDefault( method => method.Name.Split('.').Last().Equals(name, StringComparison.Ordinal) && method.GetParameters().Count() == args.Length && method.GetParameters().Select( (parameter, index) => parameter.ParameterType.IsAssignableFrom(args[index].GetType())).Aggregate( true, (a, b) => a && b)); } internal static FieldInfo GetTypeField(this Type type, string name) { return type.GetFields( BindingFlags.GetField | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic).FirstOrDefault( field => field.Name.Equals(name, StringComparison.Ordinal)); } internal static PropertyInfo GetTypeProperty(this Type type, string name) { return type.GetProperties( BindingFlags.GetProperty | BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic).FirstOrDefault( property => property.Name.Equals(name, StringComparison.Ordinal)); } // Other extension methods are not listed. } So now, when invoked, TryGetMember() searches the specified member and invoke it. The code can be written like this: dynamic dynamicDatabase = new DynamicWrapper<NorthwindDataContext>(ref database); dynamic dynamicReturnValue = dynamicDatabase.Provider.Execute(query.Expression).ReturnValue; This greatly simplified reflection. ToDynamic() and fluent reflection To make it even more straight forward, A ToDynamic() method is provided: public static class DynamicWrapperExtensions { public static dynamic ToDynamic<T>(this T value) { return new DynamicWrapper<T>(ref value); } } and a ToStatic() method is provided to unwrap the value: public class DynamicWrapper<T> : DynamicObject { public T ToStatic() { return this._value; } } In the above TryGetMember() method, please notice it does not output the member’s value, but output a wrapped member value (that is, memberValue.ToDynamic()). This is very important to make the reflection fluent. Now the code becomes: IEnumerable<Product> results = database.ToDynamic() // Here starts fluent reflection. .Provider.Execute(query.Expression).ReturnValue .ToStatic(); // Unwraps to get the static value. With the help of TryConvert(): public class DynamicWrapper<T> : DynamicObject { public override bool TryConvert(ConvertBinder binder, out object result) { result = this._value; return true; } } ToStatic() can be omitted: IEnumerable<Product> results = database.ToDynamic() .Provider.Execute(query.Expression).ReturnValue; // Automatically converts to expected static value. Take a look at the reflection code at the beginning of this post again. Now it is much much simplified! Special scenarios In 90% of the scenarios ToDynamic() is enough. But there are some special scenarios. Access static members Using extension method ToDynamic() for accessing static members does not make sense. Instead, DynamicWrapper<T> has a parameterless constructor to handle these scenarios: public class DynamicWrapper<T> : DynamicObject { public DynamicWrapper() // For static. { this._type = typeof(T); this._isValueType = this._type.IsValueType; } } The reflection code should be like this: dynamic wrapper = new DynamicWrapper<StaticClass>(); int value = wrapper._value; int result = wrapper.PrivateMethod(); So accessing static member is also simple, and fluent of course. Change instances of value types Value type is much more complex. The main problem is, value type is copied when passing to a method as a parameter. This is why ref keyword is used for the constructor. That is, if a value type instance is passed to DynamicWrapper<T>, the instance itself will be stored in this._value of DynamicWrapper<T>. Without the ref keyword, when this._value is changed, the value type instance itself does not change. Consider FieldInfo.SetValue(). In the value type scenarios, invoking FieldInfo.SetValue(this._value, value) does not change this._value, because it changes the copy of this._value. I searched the Web and found a solution for setting the value of field: internal static class FieldInfoExtensions { internal static void SetValue<T>(this FieldInfo field, ref T obj, object value) { if (typeof(T).IsValueType) { field.SetValueDirect(__makeref(obj), value); // For value type. } else { field.SetValue(obj, value); // For reference type. } } } Here __makeref is a undocumented keyword of C#. But method invocation has problem. This is the source code of TryInvokeMember(): public override bool TryInvokeMember(InvokeMemberBinder binder, object[] args, out object result) { if (binder == null) { throw new ArgumentNullException("binder"); } MethodInfo method = this._type.GetTypeMethod(binder.Name, args) ?? this._type.GetInterfaceMethod(binder.Name, args) ?? this._type.GetBaseMethod(binder.Name, args); if (method != null) { // Oops! // If the returnValue is a struct, it is copied to heap. object resultValue = method.Invoke(this._value, args); // And result is a wrapper of that copied struct. result = new DynamicWrapper<object>(ref resultValue); return true; } result = null; return false; } If the returned value is of value type, it will definitely copied, because MethodInfo.Invoke() does return object. If changing the value of the result, the copied struct is changed instead of the original struct. And so is the property and index accessing. They are both actually method invocation. For less confusion, setting property and index are not allowed on struct. Conclusions The DynamicWrapper<T> provides a simplified solution for reflection programming. It works for normal classes (reference types), accessing both instance and static members. In most of the scenarios, just remember to invoke ToDynamic() method, and access whatever you want: StaticType result = someValue.ToDynamic()._field.Method().Property[index]; In some special scenarios which requires changing the value of a struct (value type), this DynamicWrapper<T> does not work perfectly. Only changing struct’s field value is supported. The source code can be downloaded from here, including a few unit test code.

Search Results

Search found 63498 results on 2540 pages for 'vb net 2010'.

Page 761/2540 | < Previous Page | 757 758 759 760 761 762 763 764 765 766 767 768 | Next Page >

- by user1487950

- by Tommy Jakobsen

- by DrFredEdison

- by mortezam

- by Stephen.Walther

- by psheriff

- by Bertrand Le Roy

- by psheriff

- by Dan Tao

- by Wayne M

- by Ahmed ilyas

- by user1595846

- by Aerovistae

- by Leron

- by bearcdp

- by Optimax

- by Jake

- by user1495181

- by Giffyguy

- by John Donahue

- by Hendrik

- by mortezam

- by hajan

- by hajan

- by Dixin

< Previous Page | 757 758 759 760 761 762 763 764 765 766 767 768 | Next Page >