Search Results

Search found 53332 results on 2134 pages for 'vb net'.

Page 4/2134 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • C#.NET vs VB.NET, Which language is better?

    Features I cannot say any language good or bad as long as it's compiler can produce MSIL can run under .NET CLR. If someone says C# has more futures, you can understand that those new features are of C# compiler but not .NET, because if C# has a specific future then CLR cannot understand them. So the new features of C# will have to convert to the code understood by CLR eventually. that means the new features are developed for C# compiler basically to facilitates the developer to write their code in better way. so that means no difference in feature list between C# and VB.NET if you think in CLR perspective. Ease of writing Code I feel writing code in C# is easy, because my background is C and C++, Java, syntaxes very are similar. I assume most developers feel the same. Readability But some people say VB.NET code most readable for the members who are from non technical background, because keywords are generally in English rather special charectors. No of Projects in Market I assume 80 percent of market uses C# in their .NET development. for example in my company many projects are there .nET and all are using C#. Productivity & Experience though the feature list is same, generally developers wants to write code in their familiar languages. because it increase the productivity. Hope this helps to choose the language which suits for you. span.fullpost {display:none;}

    Read the article

  • C#.NET vs VB.NET, Which language is better?

    Features I cannot say any language good or bad as long as it's compiler can produce MSIL can run under .NET CLR. If someone says C# has more futures, you can understand that those new features are of C# compiler but not .NET, because if C# has a specific future then CLR cannot understand them. So the new features of C# will have to convert to the code understood by CLR eventually. that means the new features are developed for C# compiler basically to facilitates the developer to write their code in better way. so that means no difference in feature list between C# and VB.NET if you think in CLR perspective. Ease of writing Code I feel writing code in C# is easy, because my background is C and C++, Java, syntaxes very are similar. I assume most developers feel the same. Readability But some people say VB.NET code most readable for the members who are from non technical background, because keywords are generally in English rather special charectors. No of Projects in Market I assume 80 percent of market uses C# in their .NET development. for example in my company many projects are there .nET and all are using C#. Productivity & Experience though the feature list is same, generally developers wants to write code in their familiar languages. because it increase the productivity. Hope this helps to choose the language which suits for you. span.fullpost {display:none;}

    Read the article

  • Customize the SimpleMembership in ASP.NET MVC 4.0

    - by thangchung
    As we know, .NET 4.5 have come up to us, and come along with a lot of new interesting features as well. Visual Studio 2012 was also introduced some days ago. They made us feel very happy with cool improvement along with us. Performance when loading code editor is very good at the moment (immediate after click on the solution). I explore some of cool features at these days. Some of them like Json.NET integrated in ASP.NET MVC 4.0, improvement on asynchronous action, new lightweight theme on Visual Studio, supporting very good on mobile development, improvement on authentication… I reviewed them, and found out that in this version of .NET Microsoft was not only developed new feature that suggest from community but also focused on improvement performance of existing features or components. Besides that, they also opened source more projects, like Entity Framework, Reactive Extensions, ASP.NET Web Stack… At the moment, I feel Microsoft want to open source more and more their projects. Today, I am going to dive in deep on new SimpleMembership model. It is really good because in this security model, Microsoft actually focus on development needs. As we know, in the past, they introduce some of provider supplied for coding security like MembershipProvider, RoleProvider… I don’t need to talk but everyone that have ever used it know that they were actually hard to use, and not easy to maintain and unit testing. Why? Because every time you inherit it, you need to override all methods inside it. Some people try to abstract it by introduce more method with virtual keyword, and try to implement basic behavior, so in the subclass we only need to override the method that need for their business. But to me, it’s only the way to work around. ASP.NET team and Web Matrix knew about it, so they built the new features based on existing components on .NET framework. And one of component that comes to us is SimpleMembership and SimpleRole. They implemented the Façade pattern on the top of those, and called it is WebSecurity. In the web, we can call WebSecurity anywhere we want, and make a call to inside wrapper of it. I read a lot of them on web blog, on technical news, on MSDN as well. Matthew Osborn had an excellent article about it at his blog. Jon Galloway had an article like this at here. He analyzed why old membership provider not fixed well to ASP.NET MVC and how to get over it. Those are very good to me. It introduced to me about how to doing SimpleMembership on it, how to doing it on new ASP.NET MVC web application. But one thing, those didn’t tell me was how to doing it on existing security model (that mean we already had Users and Roles on legacy system, and how we can integrate it to this system), that’s a reason I will introduce it today. I have spent couples of hours to see what’s inside this, and try to make one example to clarify my concern. And it’s lucky that I can make it working well.The first thing, we need to create new ASP.NET MVC application on Visual Studio 2012. We need to choose Internet type for this web application. ASP.NET MVC actually creates all needs components for the basic membership and basic role. The cool feature is DoNetOpenAuth come along with it that means we can log-in using facebook, twitter or Windows Live if you want. But it’s only for LocalDb, so we need to change it to fix with existing database model on SQL Server. The next step we have to make SimpleMembership can understand which database we use and show it which column need to point to for the ID and UserName. I really like this feature because SimpleMembership on need to know about the ID and UserName, and they don’t care about rest of it. I assume that we have an existing database model like So we will point it in code like The codes for it, we put on InitializeSimpleMembershipAttribute like [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = true)]     public sealed class InitializeSimpleMembershipAttribute : ActionFilterAttribute     {         private static SimpleMembershipInitializer _initializer;         private static object _initializerLock = new object();         private static bool _isInitialized;         public override void OnActionExecuting(ActionExecutingContext filterContext)         {             // Ensure ASP.NET Simple Membership is initialized only once per app start             LazyInitializer.EnsureInitialized(ref _initializer, ref _isInitialized, ref _initializerLock);         }         private class SimpleMembershipInitializer         {             public SimpleMembershipInitializer()             {                 try                 {                     WebSecurity.InitializeDatabaseConnection("DefaultDb", "User", "Id", "UserName", autoCreateTables: true);                 }                 catch (Exception ex)                 {                     throw new InvalidOperationException("The ASP.NET Simple Membership database could not be initialized. For more information, please see http://go.microsoft.com/fwlink/?LinkId=256588", ex);                 }             }         }     }And decorating it in the AccountController as below [Authorize]     [InitializeSimpleMembership]     public class AccountController : ControllerIn this case, assuming that we need to override the ValidateUser to point this to existing User database table, and validate it. We have to add one more class like public class CustomAdminMembershipProvider : SimpleMembershipProvider     {         // TODO: will do a better way         private const string SELECT_ALL_USER_SCRIPT = "select * from [dbo].[User]private where UserName = '{0}'";         private readonly IEncrypting _encryptor;         private readonly SimpleSecurityContext _simpleSecurityContext;         public CustomAdminMembershipProvider(SimpleSecurityContext simpleSecurityContext)             : this(new Encryptor(), new SimpleSecurityContext("DefaultDb"))         {         }         public CustomAdminMembershipProvider(IEncrypting encryptor, SimpleSecurityContext simpleSecurityContext)         {             _encryptor = encryptor;             _simpleSecurityContext = simpleSecurityContext;         }         public override bool ValidateUser(string username, string password)         {             if (string.IsNullOrEmpty(username))             {                 throw new ArgumentException("Argument cannot be null or empty", "username");             }             if (string.IsNullOrEmpty(password))             {                 throw new ArgumentException("Argument cannot be null or empty", "password");             }             var hash = _encryptor.Encode(password);             using (_simpleSecurityContext)             {                 var users =                     _simpleSecurityContext.Users.SqlQuery(                         string.Format(SELECT_ALL_USER_SCRIPT, username));                 if (users == null && !users.Any())                 {                     return false;                 }                 return users.FirstOrDefault().Password == hash;             }         }     }SimpleSecurityDataContext at here public class SimpleSecurityContext : DbContext     {         public DbSet<User> Users { get; set; }         public SimpleSecurityContext(string connStringName) :             base(connStringName)         {             this.Configuration.LazyLoadingEnabled = true;             this.Configuration.ProxyCreationEnabled = false;         }         protected override void OnModelCreating(DbModelBuilder modelBuilder)         {             base.OnModelCreating(modelBuilder);                          modelBuilder.Configurations.Add(new UserMapping());         }     }And Mapping for User as below public class UserMapping : EntityMappingBase<User>     {         public UserMapping()         {             this.Property(x => x.UserName);             this.Property(x => x.DisplayName);             this.Property(x => x.Password);             this.Property(x => x.Email);             this.ToTable("User");         }     }One important thing, you need to modify the web.config to point to our customize SimpleMembership <membership defaultProvider="AdminMemberProvider" userIsOnlineTimeWindow="15">       <providers>         <clear/>         <add name="AdminMemberProvider" type="CIK.News.Web.Infras.Security.CustomAdminMembershipProvider, CIK.News.Web.Infras" />       </providers>     </membership>     <roleManager enabled="false">       <providers>         <clear />         <add name="AdminRoleProvider" type="CIK.News.Web.Infras.Security.AdminRoleProvider, CIK.News.Web.Infras" />       </providers>     </roleManager>The good thing at here is we don’t need to modify the code on AccountController. We only need to modify on SimpleMembership and Simple Role (if need). Now build all solutions, run it. We should see a screen like thisIf I login to Twitter button at the bottom of this page, we will be transfer to twitter authentication pageYou have to waiting for a moment Afterwards it will transfer you back to your admin screenYou can find all source codes at my MSDN code. I will really happy if you guys feel free to put some comments as below. It will be helpful to improvement my code in the future. Thank for all your readings. 

    Read the article

  • Migrating ASP.NET MVC 1.0 applications to ASP.NET MVC 2 RTM

    - by Eilon
    Note: ASP.NET MVC 2 RTM isn’t yet released! But this tool will help you get your ASP.NET MVC 1.0 applications ready for when it is! I have updated the MVC App Converter to convert projects from ASP.NET MVC 1.0 to ASP.NET MVC 2 RTM. This should be last the last major change to the MVC App Converter that I released previews of in the past several months. Download The app is a single executable: Download MvcAppConverter-MVC2RTM.zip (255 KB). Usage The only requirement for this tool is that you have .NET Framework 3.5 SP1 on the machine. You do not need to have Visual Studio or ASP.NET MVC installed (unless you want to open your project!). Even though the tool performs an automatic backup of your solution it is recommended that you perform a manual backup of your solution as well. To convert an ASP.NET MVC 1.0 project built with Visual Studio 2008 to an ASP.NET MVC 2 project in Visual Studio 2008 perform these steps: Launch the converter Select the solution Click the “Convert” button To convert an ASP.NET MVC 1.0 project built with Visual Studio 2008 to an ASP.NET MVC 2 project in Visual Studio 2010: Wait until Visual Studio 2010 is released (next month!) and it will have a built-in version of this tool that will run automatically when you open an ASP.NET MVC 1.0 project Perform the above steps, then open the project in Visual Studio 2010 and it will perform the remaining conversion steps What it can do Open up ASP.NET MVC 1.0 projects from Visual Studio 2008 (no other versions of ASP.NET MVC or Visual Studio are supported) Create a full backup of your solution’s folder For every VB or C# project that has a reference to System.Web.Mvc.dll it will (this includes ASP.NET MVC web application projects as well as ASP.NET MVC test projects): Update references to ASP.NET MVC 2 Add a reference to System.ComponentModel.DataAnnotations 3.5 (if not already present) For every VB or C# ASP.NET MVC Web Application it will: Change the project type to an ASP.NET MVC 2 project Update the root ~/web.config references to ASP.NET MVC 2 Update the root ~/web.config to have a binding redirect from ASP.NET MVC 1.0 to ASP.NET MVC 2 Update the ~/Views/web.config references to ASP.NET MVC 2 Add or update the JavaScript files (add jQuery, add jQuery.Validate, add Microsoft AJAX, add/update Microsoft MVC AJAX, add Microsoft MVC Validation adapter) Unknown project types or project types that have nothing to do with ASP.NET MVC will not be updated What it can’t do It cannot convert projects directly to Visual Studio 2010 or to .NET Framework 4. It can have issues if your solution contains projects that are not located under the solution directory. If you are using a source control system it might have problems overwriting files. It is recommended that before converting you check out all files from the source control system. It cannot change code in the application that might need to be changed due to breaking changes between ASP.NET MVC 1.0 and ASP.NET MVC 2. Feedback, Please! If you need to convert a project to ASP.NET MVC 2 please try out this application and hopefully you’re good to go. If you spot any bugs or features that don’t work leave a comment here and I will try to address these issues in an updated release.

    Read the article

  • Is VB Really Case Insensitive?

    - by Otaku
    I'm not trying to start an argument here, but for whatever reason it's typically stated that VB is case insensitive and C languages aren't (and somehow that is a good thing). But here's my question: Where exactly is VB case insensitive? When I type... Dim ss As String Dim SS As String ...into the VS2008 IDE the second one has a warning of "Local variable 'SS' is already declared in the current block". In VBA VBE, it doesn't immediately kick an error, but rather just auto-corrects the case. Am I missing something here with this argument that VB is not case sensitive? (Also, if you know or care to answer, why would that be a bad thing?) EDIT: Why am I even asking this question? I've used VB in many of it's dialects for years now, sometimes as a hobbyist, sometimes for small business-related programs in a workgroup. As of the last 6 months I've been working on a big project, much bigger than I anticipated. Much of the sample source code out there is in C#. I don't have any burning desire to learn C#, but if there are things I'm missing out on that C# offers that VB doesn't (an opposite would be VB.NET offers XML Literals), then I'd like to know more about that feature. So in this case, it's often argued that C languages are case sensitive and that's good and VB is case insensitive and that is bad. I'd like to know A) how exactly is VB case insensitive because every single example in the code editor becomes case sensititive (meaning case gets corrected) whether I want it or not and B) is this compelling enough for me to consider moving to C# if VB.NET case is somehow limiting what I could do with code?

    Read the article

  • Adding page title to each page while creating a PDF file using itextsharp in VB.NET

    - by Snowy
    I have recently started using itextsharp and gradually learning it. So far I created a PDF file and it seems great. I have added a table and some subtables as the first table cells to hold data. It is done using two for loops. The first one loops through all data and the second one is each individual data displayed in columns. The html outcome looks like the following: <table> <tr> <td>Page title in center</td> </tr> <tr> <td> <table> <tr> <td>FirstPersonName</td> <td>Rank1</td> <td>info1a</td> <td>infob</td> <td>infoc</td> </tr> </table> </td> <td> <table> <tr> <td>SecondPersonName</td> <td>Rank2</td> <td>info1a</td> <td>infob</td> <td>infoc</td> <td>infod</td> <td>infoe</td> </tr> </table> </td> <td> <table> <tr> <td>ThirdPersonName</td> <td>Rank2</td> <td>info1a</td> <td>infob</td> <td>infoc</td> <td>infod</td> <td>infoe</td> <td>infof</td> <td>infog</td> </tr> </table> </td> </tr> </table> For page headings, I added a cell at the top before any other cells. I need to add this heading to all pages. Depending on the size of data, some pages have two rows and some pages have three rows of data. So I can not tell exactly when the new page starts to add the heading/title. My question is how to add the heading/title to all pages. I use VB.net. I searched for answer online and had no success. Your help would be greatly appreciated.

    Read the article

  • Why is VB so popular? [closed]

    - by aaaidan
    To me, Visual Basic seems clumsy, ugly, error-prone, and difficult to read. I'll let others explain why. While VB.net has clearly been a huge leap forward for the language in terms of features, I still don't understand why anyone would choose to code in VB over, say, C#. However, I still see (what seems to be) the vast majority of commercial web apps from "MS shops" are built in VB. I could stand corrected on this, but VB still seems more popular than it deserves. Can anyone help answer any (or all) of these questions: Am I missing something with VB? Is it easier to learn, or "friendlier" than C#? Are there features I don't know about? Why is VB/VB.net so frequently used today, especially in web projects?

    Read the article

  • ASP.NET Error Handling: Creating an extension method to send error email

    - by Jalpesh P. Vadgama
    Error handling in asp.net required to handle any kind of error occurred. We all are using that in one or another scenario. But some errors are there which will occur in some specific scenario in production environment in this case We can’t show our programming errors to the End user. So we are going to put a error page over there or whatever best suited as per our requirement. But as a programmer we should know that error so we can track the scenario and we can solve that error or can handle error. In this kind of situation an Error Email comes handy. Whenever any occurs in system it will going to send error in our email. Here I am going to write a extension method which will send errors in email. From asp.net 3.5 or higher version of .NET framework  its provides a unique way to extend your classes. Here you can fine more information about extension method. So lets create extension method via implementing a static class like following. I am going to use same code for sending email via my Gmail account from here. Following is code for that. using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Net.Mail; namespace Experiement { public static class MyExtension { public static void SendErrorEmail(this Exception ex) { MailMessage mailMessage = new MailMessage(new MailAddress("[email protected]") , new MailAddress("[email protected]")); mailMessage.Subject = "Exception Occured in your site"; mailMessage.IsBodyHtml = true; System.Text.StringBuilder errorMessage = new System.Text.StringBuilder(); errorMessage.AppendLine(string.Format("<B>{0}</B>:{1}<BR/>","Exception",ex.Message)); errorMessage.AppendLine(string.Format("<B>{0}</B>:{1}<BR/>", "Stack Trace", ex.StackTrace)); if (ex.InnerException != null) { errorMessage.AppendLine(string.Format("<B>{0}</B>:{1}<BR/>", " Inner Exception", ex.InnerException.Message)); errorMessage.AppendLine(string.Format("<B>{0}</B>:{1}<BR/>", "Inner Stack Trace", ex.InnerException.StackTrace)); } mailMessage.Body = errorMessage.ToString(); System.Net.NetworkCredential networkCredentials = new System.Net.NetworkCredential("[email protected]", "password"); SmtpClient smtpClient = new SmtpClient(); smtpClient.EnableSsl = true; smtpClient.UseDefaultCredentials = false; smtpClient.Credentials = networkCredentials; smtpClient.Host = "smtp.gmail.com"; smtpClient.Port = 587; smtpClient.Send(mailMessage); } } } After creating an extension method let us that extension method to handle error like following in page load event of page. using System; namespace Experiement { public partial class WebForm1 : System.Web.UI.Page { protected void Page_Load(object sender,System.EventArgs e) { try { throw new Exception("My custom Exception"); } catch (Exception ex) { ex.SendErrorEmail(); Response.Write(ex.Message); } } } } Now in above code I have generated custom exception for example but in production It can be any Exception. And you can see I have use ex.SendErrorEmail() function in catch block to send email. That’s it.. Now it will throw exception and you will email in your email box like below.   That’s its. It’s so simple…Stay tuned for more.. Happy programming.. Technorati Tags: Exception,Extension Mehtod,Error Handling,ASP.NET

    Read the article

  • ASP.NET 4.0- Html Encoded Expressions

    - by Jalpesh P. Vadgama
    We all know <%=expression%> features in asp.net. We can print any string on page from there. Mostly we are using them in asp.net mvc. Now we have one new features with asp.net 4.0 that we have HTML Encoded Expressions and this prevent Cross scripting attack as we are html encoding them. ASP.NET 4.0 introduces a new expression syntax <%: expression %> which automatically convert string into html encoded. Let’s take an example for that. I have just created an hello word protected method which will return a simple string which contains characters that needed to be HTML Encoded. Below is code for that. protected static string HelloWorld() { return "Hello World!!! returns from function()!!!>>>>>>>>>>>>>>>>>"; } Now let’s use the that hello world in our page html like below. I am going to use both expression to give you exact difference. <form id="form1" runat="server"> <div> <strong><%: HelloWorld()%></strong> </div> <div> <strong><%= HelloWorld()%></strong> </div> </form> Now let’s run the application and you can see in browser both look similar. But when look into page source html in browser like below you can clearly see one is HTML Encoded and another one is not. That’s it.. It’s cool.. Stay tuned for more.. Happy Programming Technorati Tags: ASP.NET 4.0,HTMLEncode,C#4.0

    Read the article

  • Daily tech links for .net and related technologies - June 14-16, 2010

    - by SanjeevAgarwal
    Daily tech links for .net and related technologies - June 14-16, 2010 Web Development ASP.Net MVC 2 Auto Complete Textbox With Custom View Model Attribute & EditorTemplate - Sean McAlinden Localization with ASP.NET MVC ModelMetadata - Kazi Manzur Rashid Securing Dynamic Data 4 (Replay) - Steve Adding Client-Side Script to an MVC Conditional Validator - Simon Ince jQuery: Storing and retrieving data related to elements - Rebecca Murphey Web Design 48 Examples of Excellent Layout in Web Design...(read more)

    Read the article

  • My View on ASP.NET Web Forms versus MVC

    - by Ricardo Peres
    Introduction A lot has been said on Web Forms and MVC, but since I was recently asked about my opinion on the subject, here it is. First, I have to say that I really like both technologies and I don’t think any is going away – just remember SharePoint, which is built on top of Web Forms. I see them as complementary, targeting different needs and leveraging different skills. Let’s go through some of their differences. Rapid Application Development Rapid Application Development (RAD) is the development process by which you have an Integrated Development Environment (IDE), a visual design surface and a toolbox, and you drag components from the toolbox to the design surface and set their properties through a property inspector. It was introduced with some of the earliest Windows graphical IDEs such as Visual Basic and Delphi. With Web Forms you have RAD out of the box. Visual Studio offers a generally good (and extensible) designer for the layout of pages and web user controls. Designing a page may simply be about dragging controls from the toolbox, setting their properties and wiring up some events to event handlers, which are implemented in code behind .NET classes. Most people will be familiar with this kind of development and enjoy it. You can see what you are doing from the beginning. MVC also has designable pages – called views in MVC terminology – the problem is that they can be built using different technologies, some of which, at the moment (MVC 4) do not support RAD – Razor, for example. I believe it is just a matter of time for that to be implemented in Visual Studio, but it will mostly consist on HTML editing, and until that day comes, you have to live with source editing. Development Model Web Forms features the same development model that you are used to from Windows Forms and other similar technologies: events fired by controls and automatic persistence of their properties between postbacks. For that, it uses concepts such as view state, which some may love and others may hate, because it may be misused quite easily, but otherwise does its job well. Another fundamental concept is data binding, by which a collection of data can be fed to a control and have it render that data somehow – just thing of the GridView control. The focus is on the page, that’s where it all starts, and you can place everything in the same code behind class: data access, business logic, layout, etc. The controls take care of generating a great part of the HTML and JavaScript for you. With MVC there is no free lunch when it comes to data persistence between requests, you have to implement it yourself. As for event handling, that is at the core of MVC, in the form of controllers and action methods, you just don’t think of them as event handlers. In MVC you need to think more in HTTP terms, so action methods such as POST and GET are relevant to you, and may write actions to handle one or the other. Also of crucial importance is model binding: the way by which MVC converts your posted data into a .NET class. This is something that ASP.NET 4.5 Web Forms has introduced as well, but it is a cornerstone in MVC. MVC also has built-in validation of these .NET classes, which out of the box uses the Data Annotations API. You have full control of the generated HTML - except for that coming from the helper methods, usually small fragments - which requires a greater familiarity with the specifications. You normally rely much more on JavaScript APIs, they are even included in the Visual Studio template, that is because much less is done for you. Reuse It is difficult to accept a professional company/project that does not employ reuse. It can save a lot of time thus cutting costs significantly. Code reused in several projects matures as time goes by and helps developers learn from past experiences. ASP.NET Web Forms was built with reuse in mind, in the form of controls. Controls encapsulate functionality and are generally portable from project to project (with the notable exception of web user controls, those with an associated .ASCX markup file). ASP.NET has dozens of controls and it is very easy to develop new ones, so I believe this is a great advantage. A control can inject JavaScript code and external references as well as generate HTML an CSS. MVC on the other hand does not use controls – it is possible to use them, with some view engines like ASPX, but it is just not advisable because it breaks the flow – where do Init, Load, PreRender, etc, fit? The most similar to controls is extension methods, or helpers. They serve the same purpose – generating HTML, CSS or JavaScript – and can be reused between different projects. What differentiates them from controls is that there is no inheritance and no context – an extension method is just a static method which doesn’t know where it is being called. You also have partial views, which you can reuse in the same project, but there is no inheritance as well. This, in my view, is a weakness of MVC. Architecture Both technologies are highly extensible. I have writtenstarted writing a series of posts on ASP.NET Web Forms extensibility and will probably write another series on MVC extensibility as well. A number of scenarios are covered in any of these models, and some extensibility points apply to both, because, of course both stand upon ASP.NET. With Web Forms, if you’re like me, you start by defining you master pages, pages and controls, with some helper classes to glue everything. You may as well throw in some JavaScript, but probably you’re main work will be with plain old .NET code. The controls you define have the chance to inject JavaScript code and references, through either the ScriptManager or the page’s ClientScript object, as well as generating HTML and CSS code. The master page and page model with code behind classes offer a number of “hooks” by which you can change the normal way of things, for example, in a page you can access any control on the master page, add script or stylesheet references to its head and even change the page’s title. Also, with Web Forms, you typically have URLs in the form “/SomePath/SomePage.aspx?SomeParameter=SomeValue”, which isn’t really SEO friendly, no to mention the HTML that some controls produce, far from standards, optimization and best practices. In MVC, you also normally start by defining the master page (or layout) and views, which are the visible parts, and then define controllers on separate files. These controllers do not know anything about the views, except the names and types of the parameters that will be passed to and from them. The controller will be responsible for the data access and business logic, eventually relying on additional classes for this purpose. On a controller you only receive parameters and return a result, which may be a request for the rendering of a view, a redirection to another URL or a JSON object, to name just a few. The controller class does not know anything about the web, so you can effectively reuse it in a non-web project. This separation and the lack of programmatic access to the UI elements, makes it very difficult to implement, for example, something like SharePoint with MVC. OK, I know about Orchard, but it isn’t really a general purpose development framework, but instead, a CMS that happens to use MVC. Not having controls render HTML for you gives you in turn much more control over it – it is your responsibility to create it, which you can either consider a blessing or a curse, in the later case, you probably shouldn’t be using MVC at all. Also MVC URLs tend to be much more SEO-oriented, if you design your controllers and actions properly. Testing In a well defined architecture, you should separate business logic, data access logic and presentation logic, because these are all different things and it might even be the need to switch one implementation for another: for example, you might design a system which includes a data access layer, a business logic layer and two presentation layers, one on top of ASP.NET and the other with WPF; and the data access layer might be implemented first using NHibernate and later on switched for Entity Framework Code First. These changes are not that rare, so care should be taken in designing the system to make them possible. Web Forms are difficult to test, because it relies on event handlers which are only fired in web contexts, when a form is submitted or a page is requested. You can call them with reflection, but you have to set up a number of mocking objects first, HttpContext.Current first coming to my mind. MVC, on the other hand, makes testing controllers a breeze, so much that it even includes a template option for generating boilerplate unit test classes up from start. A well designed – from the unit test point of view - controller will receive everything it needs to work as parameters to its action methods, so you can pass whatever values you need very easily. That doesn’t mean, of course, that everything can be tested: views, for instance, are difficult to test without actually accessing the site, but MVC offers the possibility to compile views at build time, so that, at least, you know you don’t have syntax errors beforehand. Myths Some popular but unfounded myths around MVC include: You cannot use controls in MVC: not true, actually, you can, at least with the Web Forms (ASPX) view engine; the declaration and usage is exactly the same as with Web Forms; You cannot specify a base class for a view: with the ASPX view engine you can use the Inherits Page directive, with this and all the others you can use the pageBaseType and userControlBaseType attributes of the <page> element; MVC shields you from doing “bad things” on your views: well, you can place any code on a code block, at least with the ASPX view engine (you may be starting to see a pattern here), even data access code; The model is the entity model, tied to an O/RM: the model is actually any class that you use to pass values to a view, including (but generally not recommended) an entity model; Unit tests come with no cost: unit tests generally don’t cover the UI, although there are frameworks just for that (see WatiN, for example); also, for some tests, you will have to mock or replace either the HttpContext.Current property or the HttpContextBase class yourself; Everything is testable: views aren’t, without accessing the site; MVC relies on HTML5/some_cool_new_javascript_framework: there is no relation whatsoever, MVC renders whatever you want it to render and does not require any framework to be present. The thing is, the subsequent releases of MVC happened in a time when Microsoft has become much more involved in standards, so the files and technologies included in the Visual Studio templates reflect this, and it just happens to work well with jQuery, for example. Conclusion Well, this is how I see it. Some folks may think that I am being too rude on MVC, probably because I don’t like it, but that’s not true: like I said, I do like MVC and I am starting my new projects with it. I just don’t want to go along with that those that say that MVC is much superior to Web Forms, in fact, some things you can do much more easily with Web Forms than with MVC. I will be more than happy to hear what you think on this!

    Read the article

  • Explained: EF 6 and “Could not determine storage version; a valid storage connection or a version hint is required.”

    - by Ken Cox [MVP]
    I have a legacy ASP.NET 3.5 web site that I’ve upgraded to a .NET 4 web application. At the same time, I upgraded to Entity Framework 6. Suddenly one of the pages returned the following error: [ArgumentException: Could not determine storage version; a valid storage connection or a version hint is required.]    System.Data.SqlClient.SqlVersionUtils.GetSqlVersion(String versionHint) +11372412    System.Data.SqlClient.SqlProviderServices.GetDbProviderManifest(String versionHint) +91    System.Data.Common.DbProviderServices.GetProviderManifest(String manifestToken) +92 [ProviderIncompatibleException: The provider did not return a ProviderManifest instance.]    System.Data.Common.DbProviderServices.GetProviderManifest(String manifestToken) +11431433    System.Data.Metadata.Edm.Loader.InitializeProviderManifest(Action`3 addError) +11370982    System.Data.EntityModel.SchemaObjectModel.Schema.HandleAttribute(XmlReader reader) +216 A search of the error message didn’t turn up anything helpful except that someone mentioned that the error messages was bogus in his case. The page in question uses the ASP.NET EntityDataSource control, consumed by a Telerik RadGrid. This is a fabulous combination for putting a huge amount of functionality on a page in a very short time. Unfortunately, the 6.0.1 release of EF6 doesn’t support EntityDataSource. According to the people in charge, support is planned but there’s no timeline for an EntityDataSource build that works with EF6.  I’m not sure what to do in the meantime. Should I back out EF6 or manually wire up the RadGrid? The upshot is that you might want to rethink plans to upgrade to Entity Framework 6 for Web forms projects if they rely on that handy control. It might also help to spend a User voice vote here:  http://data.uservoice.com/forums/72025-entity-framework-feature-suggestions/suggestions/3702890-support-for-asp-net-entitydatasource-and-dynamicda

    Read the article

  • DevDays ‘00 The Netherlands day #1

    - by erwin21
    First day of DevDays 2010, I was looking forward to DevDays to see all the new things like VS2010, .NET4.0, MVC2. The lineup for this year is again better than the year before, there are 100+ session of all kind of topics like Cloud, Database, Mobile, SharePoint, User experience, Visual Studio, Web. The first session of the day was a keynote by Anders Hejlsberg he talked about the history and future of programming languages. He gave his view about trends and influences in programming languages today and in the future. The second talk that i followed was from the famous Scott Hanselman, he talked about the basics of ASP.NET MVC 2, although it was a 300 level session, it was more like a level 100 session, but it was mentioned by Scott at the beginning. Although it was interesting to see all the basic things about MVC like the controllers, actions, routes, views, models etc. After the lunch the third talk for me was about moving ASP.NET webform applications to MVC from Fritz Onion. In this session he changed an example webform application part by part to a MVC application. He gave some interesting tips and tricks and showed how to solve some issues that occur while converting. Next and the fourth talk was about the difference between LINQ to SQL and  the ADO.NET  Entity Framework from Kurt Claeys. He gave a good understanding about this two options, the demos where in LINQ to SQL and the Entity Framework, the goal was to get a good understanding when and where to use both options. The last talk about this day was also from Scott Hanselman, he goes deeper into the features of ASP.NET MVC 2 and gave some interesting tips, the ninja black belt tips. He gave some tips about the tooling, the new MVC 2 html helper methods, other view engines (like NHaml, spark),T4 templating. With this tips we can be more productive and create web applications better and faster. It was a long and interesting day, I am looking forward to day #2.

    Read the article

  • Implementing History Support using jQuery for AJAX websites built on asp.net AJAX

    - by anil.kasalanati
    Problem Statement: Most modern day website use AJAX for page navigation and gone are the days of complete HTTP redirection so it is imperative that we support back and forward buttons on the browser so that end users navigation is not broken. In this article we discuss about solutions which are already available and problems with them. Microsoft History Support: Post .Net 3.5 sp1 Microsoft’s Script manager supports history for websites using Update panels. This is achieved by enabling the ENABLE HISTORY property for the script manager and then the event “Page_Browser_Navigate” needs to be handled. So whenever the browser buttons are clicked the event is fired and the application can write code to do the navigation. The following articles provide good tutorials on how to do that http://www.asp.net/aspnet-in-net-35-sp1/videos/introduction-to-aspnet-ajax-history http://www.codeproject.com/KB/aspnet/ajaxhistorymanagement.aspx And Microsoft api internally creates an IFrame and changes the bookmark of the url. Unfortunately this has a bug and it does not work in Ie6 and 7 which are the major browsers but it works in ie8 and Firefox. And Microsoft has apparently fixed this bug in .Net 4.0. Following is the blog http://weblogs.asp.net/joshclose/archive/2008/11/11/asp-net-ajax-addhistorypoint-bug.aspx For solutions which are still running on .net 3.5 sp1 there is no solution which Microsoft offers so there is  are two way to solve this o   Disable the back button. o   Develop custom solution.   Disable back button Even though this might look like a very simple thing to do there are issues around doing this  because there is no event which can be manipulated from the javascript. The browser does not provide an api to do this. So most of the technical solution on internet offer work arounds like doing a history.forward(1) so that even if the user clicks a back button the destination page redirects the user to the original page. This is not a good customer experience and does not work for asp.net website where there are different views in the same page. There are other ways around detecting the window unload events and writing code there. So there are 2 events onbeforeUnload and onUnload and we can write code to show a confirmation message to the user. If we write code in onUnLoad then we can only show a message but it is too late to stop the navigation. And if we write on onBeforeUnLoad we can stop the navigation if the user clicks cancel but this event would be triggered for all AJAX calls and hyperlinks where the href is anything other than #. We can do this but the website has to be checked properly to ensure there are no links where href is not # otherwise the user would see a popup message saying “you are leaving the website”. Believe me after doing a lot of research on the back button disable I found it easier to support it rather than disabling the button. So I am going to discuss a solution which work  using jQuery with some tweaking. Custom Solution JQuery already provides an api to manage the history of a AJAX website - http://plugins.jquery.com/project/history We need to integrate this with Microsoft Page request manager so that both of them work in tandem. The page state is maintained in the cookie so that it can be passed to the server and I used jQuery cookie plug in for that – http://plugins.jquery.com/node/1386/release Firstly when the page loads there is a need to hook up all the events on the page which needs to cause browser history and following is the code to that. jQuery(document).ready(function() {             // Initialize history plugin.             // The callback is called at once by present location.hash.             jQuery.history.init(pageload);               // set onlick event for buttons             jQuery("a[@rel='history']").click(function() {                 //                 var hash = this.page;                 hash = hash.replace(/^.*#/, '');                 isAsyncPostBack = true;                 // moves to a new page.                 // pageload is called at once.                 jQuery.history.load(hash);                 return true;             });         }); The above scripts basically gets all the DOM objects which have the attribute rel=”history” and add the event. In our test page we have the link button  which has the attribute rel set to history. <asp:LinkButton ID="Previous" rel="history" runat="server" onclick="PreviousOnClick">Previous</asp:LinkButton> <asp:LinkButton ID="AsyncPostBack" rel="history" runat="server" onclick="NextOnClick">Next</asp:LinkButton> <asp:LinkButton ID="HistoryLinkButton" runat="server" style="display:none" onclick="HistoryOnClick"></asp:LinkButton>   And you can see that there is an hidden HistoryLinkButton which used to send a sever side postback in case of browser back or previous buttons. And note that we need to use display:none and not visible= false because asp.net AJAX would disallow any post backs if visible=false. And in general the pageload event get executed on the client side when a back or forward is pressed and the function is shown below function pageload(hash) {                   if (hash) {                         if (!isAsyncPostBack) {                           jQuery.cookie("page", hash);                     __doPostBack("HistoryLinkButton", "");                 }                isAsyncPostBack = false;                             } else {                 // start page             jQuery("#load").empty();             }         }   As you can see in case there is an hash in the url we are basically do an asp.net AJAX post back using the following statement __doPostBack("HistoryLinkButton", ""); So whenever the user clicks back or forward the post back happens using the event statement we provide and Previous event code is invoked in the code behind.  We need to have the code to use the pageId present in the url to change the page content. And there is an important thing to note – because the hash is worked out using the pageId’s there is a need to recalculate the hash after every AJAX post back so following code is plugged in function ReWorkHash() {             jQuery("a[@rel='history']").unbind("click");             jQuery("a[@rel='history']").click(function() {                 //                 var hash = jQuery(this).attr("page");                 hash = hash.replace(/^.*#/, '');                 jQuery.cookie("page", hash);                 isAsyncPostBack = true;                                   // moves to a new page.                 // pageload is called at once.                 jQuery.history.load(hash);                 return true;             });        }   This code is executed from the code behind using ScriptManager RegisterClientScriptBlock as shown below –       ScriptManager.RegisterClientScriptBlock(this, typeof(_Default), "Recalculater", "ReWorkHash();", true);   A sample application is available to be downloaded at the following location – http://techconsulting.vpscustomer.com/Source/HistoryTest.zip And a working sample is available at – http://techconsulting.vpscustomer.com/Samples/Default.aspx

    Read the article

  • New features of C# 4.0

    This article covers New features of C# 4.0. Article has been divided into below sections. Introduction. Dynamic Lookup. Named and Optional Arguments. Features for COM interop. Variance. Relationship with Visual Basic. Resources. Other interested readings… 22 New Features of Visual Studio 2008 for .NET Professionals 50 New Features of SQL Server 2008 IIS 7.0 New features Introduction It is now close to a year since Microsoft Visual C# 3.0 shipped as part of Visual Studio 2008. In the VS Managed Languages team we are hard at work on creating the next version of the language (with the unsurprising working title of C# 4.0), and this document is a first public description of the planned language features as we currently see them. Please be advised that all this is in early stages of production and is subject to change. Part of the reason for sharing our plans in public so early is precisely to get the kind of feedback that will cause us to improve the final product before it rolls out. Simultaneously with the publication of this whitepaper, a first public CTP (community technology preview) of Visual Studio 2010 is going out as a Virtual PC image for everyone to try. Please use it to play and experiment with the features, and let us know of any thoughts you have. We ask for your understanding and patience working with very early bits, where especially new or newly implemented features do not have the quality or stability of a final product. The aim of the CTP is not to give you a productive work environment but to give you the best possible impression of what we are working on for the next release. The CTP contains a number of walkthroughs, some of which highlight the new language features of C# 4.0. Those are excellent for getting a hands-on guided tour through the details of some common scenarios for the features. You may consider this whitepaper a companion document to these walkthroughs, complementing them with a focus on the overall language features and how they work, as opposed to the specifics of the concrete scenarios. C# 4.0 The major theme for C# 4.0 is dynamic programming. Increasingly, objects are “dynamic” in the sense that their structure and behavior is not captured by a static type, or at least not one that the compiler knows about when compiling your program. Some examples include a. objects from dynamic programming languages, such as Python or Ruby b. COM objects accessed through IDispatch c. ordinary .NET types accessed through reflection d. objects with changing structure, such as HTML DOM objects While C# remains a statically typed language, we aim to vastly improve the interaction with such objects. A secondary theme is co-evolution with Visual Basic. Going forward we will aim to maintain the individual character of each language, but at the same time important new features should be introduced in both languages at the same time. They should be differentiated more by style and feel than by feature set. The new features in C# 4.0 fall into four groups: Dynamic lookup Dynamic lookup allows you to write method, operator and indexer calls, property and field accesses, and even object invocations which bypass the C# static type checking and instead gets resolved at runtime. Named and optional parameters Parameters in C# can now be specified as optional by providing a default value for them in a member declaration. When the member is invoked, optional arguments can be omitted. Furthermore, any argument can be passed by parameter name instead of position. COM specific interop features Dynamic lookup as well as named and optional parameters both help making programming against COM less painful than today. On top of that, however, we are adding a number of other small features that further improve the interop experience. Variance It used to be that an IEnumerable<string> wasn’t an IEnumerable<object>. Now it is – C# embraces type safe “co-and contravariance” and common BCL types are updated to take advantage of that. Dynamic Lookup Dynamic lookup allows you a unified approach to invoking things dynamically. With dynamic lookup, when you have an object in your hand you do not need to worry about whether it comes from COM, IronPython, the HTML DOM or reflection; you just apply operations to it and leave it to the runtime to figure out what exactly those operations mean for that particular object. This affords you enormous flexibility, and can greatly simplify your code, but it does come with a significant drawback: Static typing is not maintained for these operations. A dynamic object is assumed at compile time to support any operation, and only at runtime will you get an error if it wasn’t so. Oftentimes this will be no loss, because the object wouldn’t have a static type anyway, in other cases it is a tradeoff between brevity and safety. In order to facilitate this tradeoff, it is a design goal of C# to allow you to opt in or opt out of dynamic behavior on every single call. The dynamic type C# 4.0 introduces a new static type called dynamic. When you have an object of type dynamic you can “do things to it” that are resolved only at runtime: dynamic d = GetDynamicObject(…); d.M(7); The C# compiler allows you to call a method with any name and any arguments on d because it is of type dynamic. At runtime the actual object that d refers to will be examined to determine what it means to “call M with an int” on it. The type dynamic can be thought of as a special version of the type object, which signals that the object can be used dynamically. It is easy to opt in or out of dynamic behavior: any object can be implicitly converted to dynamic, “suspending belief” until runtime. Conversely, there is an “assignment conversion” from dynamic to any other type, which allows implicit conversion in assignment-like constructs: dynamic d = 7; // implicit conversion int i = d; // assignment conversion Dynamic operations Not only method calls, but also field and property accesses, indexer and operator calls and even delegate invocations can be dispatched dynamically: dynamic d = GetDynamicObject(…); d.M(7); // calling methods d.f = d.P; // getting and settings fields and properties d[“one”] = d[“two”]; // getting and setting thorugh indexers int i = d + 3; // calling operators string s = d(5,7); // invoking as a delegate The role of the C# compiler here is simply to package up the necessary information about “what is being done to d”, so that the runtime can pick it up and determine what the exact meaning of it is given an actual object d. Think of it as deferring part of the compiler’s job to runtime. The result of any dynamic operation is itself of type dynamic. Runtime lookup At runtime a dynamic operation is dispatched according to the nature of its target object d: COM objects If d is a COM object, the operation is dispatched dynamically through COM IDispatch. This allows calling to COM types that don’t have a Primary Interop Assembly (PIA), and relying on COM features that don’t have a counterpart in C#, such as indexed properties and default properties. Dynamic objects If d implements the interface IDynamicObject d itself is asked to perform the operation. Thus by implementing IDynamicObject a type can completely redefine the meaning of dynamic operations. This is used intensively by dynamic languages such as IronPython and IronRuby to implement their own dynamic object models. It will also be used by APIs, e.g. by the HTML DOM to allow direct access to the object’s properties using property syntax. Plain objects Otherwise d is a standard .NET object, and the operation will be dispatched using reflection on its type and a C# “runtime binder” which implements C#’s lookup and overload resolution semantics at runtime. This is essentially a part of the C# compiler running as a runtime component to “finish the work” on dynamic operations that was deferred by the static compiler. Example Assume the following code: dynamic d1 = new Foo(); dynamic d2 = new Bar(); string s; d1.M(s, d2, 3, null); Because the receiver of the call to M is dynamic, the C# compiler does not try to resolve the meaning of the call. Instead it stashes away information for the runtime about the call. This information (often referred to as the “payload”) is essentially equivalent to: “Perform an instance method call of M with the following arguments: 1. a string 2. a dynamic 3. a literal int 3 4. a literal object null” At runtime, assume that the actual type Foo of d1 is not a COM type and does not implement IDynamicObject. In this case the C# runtime binder picks up to finish the overload resolution job based on runtime type information, proceeding as follows: 1. Reflection is used to obtain the actual runtime types of the two objects, d1 and d2, that did not have a static type (or rather had the static type dynamic). The result is Foo for d1 and Bar for d2. 2. Method lookup and overload resolution is performed on the type Foo with the call M(string,Bar,3,null) using ordinary C# semantics. 3. If the method is found it is invoked; otherwise a runtime exception is thrown. Overload resolution with dynamic arguments Even if the receiver of a method call is of a static type, overload resolution can still happen at runtime. This can happen if one or more of the arguments have the type dynamic: Foo foo = new Foo(); dynamic d = new Bar(); var result = foo.M(d); The C# runtime binder will choose between the statically known overloads of M on Foo, based on the runtime type of d, namely Bar. The result is again of type dynamic. The Dynamic Language Runtime An important component in the underlying implementation of dynamic lookup is the Dynamic Language Runtime (DLR), which is a new API in .NET 4.0. The DLR provides most of the infrastructure behind not only C# dynamic lookup but also the implementation of several dynamic programming languages on .NET, such as IronPython and IronRuby. Through this common infrastructure a high degree of interoperability is ensured, but just as importantly the DLR provides excellent caching mechanisms which serve to greatly enhance the efficiency of runtime dispatch. To the user of dynamic lookup in C#, the DLR is invisible except for the improved efficiency. However, if you want to implement your own dynamically dispatched objects, the IDynamicObject interface allows you to interoperate with the DLR and plug in your own behavior. This is a rather advanced task, which requires you to understand a good deal more about the inner workings of the DLR. For API writers, however, it can definitely be worth the trouble in order to vastly improve the usability of e.g. a library representing an inherently dynamic domain. Open issues There are a few limitations and things that might work differently than you would expect. · The DLR allows objects to be created from objects that represent classes. However, the current implementation of C# doesn’t have syntax to support this. · Dynamic lookup will not be able to find extension methods. Whether extension methods apply or not depends on the static context of the call (i.e. which using clauses occur), and this context information is not currently kept as part of the payload. · Anonymous functions (i.e. lambda expressions) cannot appear as arguments to a dynamic method call. The compiler cannot bind (i.e. “understand”) an anonymous function without knowing what type it is converted to. One consequence of these limitations is that you cannot easily use LINQ queries over dynamic objects: dynamic collection = …; var result = collection.Select(e => e + 5); If the Select method is an extension method, dynamic lookup will not find it. Even if it is an instance method, the above does not compile, because a lambda expression cannot be passed as an argument to a dynamic operation. There are no plans to address these limitations in C# 4.0. Named and Optional Arguments Named and optional parameters are really two distinct features, but are often useful together. Optional parameters allow you to omit arguments to member invocations, whereas named arguments is a way to provide an argument using the name of the corresponding parameter instead of relying on its position in the parameter list. Some APIs, most notably COM interfaces such as the Office automation APIs, are written specifically with named and optional parameters in mind. Up until now it has been very painful to call into these APIs from C#, with sometimes as many as thirty arguments having to be explicitly passed, most of which have reasonable default values and could be omitted. Even in APIs for .NET however you sometimes find yourself compelled to write many overloads of a method with different combinations of parameters, in order to provide maximum usability to the callers. Optional parameters are a useful alternative for these situations. Optional parameters A parameter is declared optional simply by providing a default value for it: public void M(int x, int y = 5, int z = 7); Here y and z are optional parameters and can be omitted in calls: M(1, 2, 3); // ordinary call of M M(1, 2); // omitting z – equivalent to M(1, 2, 7) M(1); // omitting both y and z – equivalent to M(1, 5, 7) Named and optional arguments C# 4.0 does not permit you to omit arguments between commas as in M(1,,3). This could lead to highly unreadable comma-counting code. Instead any argument can be passed by name. Thus if you want to omit only y from a call of M you can write: M(1, z: 3); // passing z by name or M(x: 1, z: 3); // passing both x and z by name or even M(z: 3, x: 1); // reversing the order of arguments All forms are equivalent, except that arguments are always evaluated in the order they appear, so in the last example the 3 is evaluated before the 1. Optional and named arguments can be used not only with methods but also with indexers and constructors. Overload resolution Named and optional arguments affect overload resolution, but the changes are relatively simple: A signature is applicable if all its parameters are either optional or have exactly one corresponding argument (by name or position) in the call which is convertible to the parameter type. Betterness rules on conversions are only applied for arguments that are explicitly given – omitted optional arguments are ignored for betterness purposes. If two signatures are equally good, one that does not omit optional parameters is preferred. M(string s, int i = 1); M(object o); M(int i, string s = “Hello”); M(int i); M(5); Given these overloads, we can see the working of the rules above. M(string,int) is not applicable because 5 doesn’t convert to string. M(int,string) is applicable because its second parameter is optional, and so, obviously are M(object) and M(int). M(int,string) and M(int) are both better than M(object) because the conversion from 5 to int is better than the conversion from 5 to object. Finally M(int) is better than M(int,string) because no optional arguments are omitted. Thus the method that gets called is M(int). Features for COM interop Dynamic lookup as well as named and optional parameters greatly improve the experience of interoperating with COM APIs such as the Office Automation APIs. In order to remove even more of the speed bumps, a couple of small COM-specific features are also added to C# 4.0. Dynamic import Many COM methods accept and return variant types, which are represented in the PIAs as object. In the vast majority of cases, a programmer calling these methods already knows the static type of a returned object from context, but explicitly has to perform a cast on the returned value to make use of that knowledge. These casts are so common that they constitute a major nuisance. In order to facilitate a smoother experience, you can now choose to import these COM APIs in such a way that variants are instead represented using the type dynamic. In other words, from your point of view, COM signatures now have occurrences of dynamic instead of object in them. This means that you can easily access members directly off a returned object, or you can assign it to a strongly typed local variable without having to cast. To illustrate, you can now say excel.Cells[1, 1].Value = "Hello"; instead of ((Excel.Range)excel.Cells[1, 1]).Value2 = "Hello"; and Excel.Range range = excel.Cells[1, 1]; instead of Excel.Range range = (Excel.Range)excel.Cells[1, 1]; Compiling without PIAs Primary Interop Assemblies are large .NET assemblies generated from COM interfaces to facilitate strongly typed interoperability. They provide great support at design time, where your experience of the interop is as good as if the types where really defined in .NET. However, at runtime these large assemblies can easily bloat your program, and also cause versioning issues because they are distributed independently of your application. The no-PIA feature allows you to continue to use PIAs at design time without having them around at runtime. Instead, the C# compiler will bake the small part of the PIA that a program actually uses directly into its assembly. At runtime the PIA does not have to be loaded. Omitting ref Because of a different programming model, many COM APIs contain a lot of reference parameters. Contrary to refs in C#, these are typically not meant to mutate a passed-in argument for the subsequent benefit of the caller, but are simply another way of passing value parameters. It therefore seems unreasonable that a C# programmer should have to create temporary variables for all such ref parameters and pass these by reference. Instead, specifically for COM methods, the C# compiler will allow you to pass arguments by value to such a method, and will automatically generate temporary variables to hold the passed-in values, subsequently discarding these when the call returns. In this way the caller sees value semantics, and will not experience any side effects, but the called method still gets a reference. Open issues A few COM interface features still are not surfaced in C#. Most notably these include indexed properties and default properties. As mentioned above these will be respected if you access COM dynamically, but statically typed C# code will still not recognize them. There are currently no plans to address these remaining speed bumps in C# 4.0. Variance An aspect of generics that often comes across as surprising is that the following is illegal: IList<string> strings = new List<string>(); IList<object> objects = strings; The second assignment is disallowed because strings does not have the same element type as objects. There is a perfectly good reason for this. If it were allowed you could write: objects[0] = 5; string s = strings[0]; Allowing an int to be inserted into a list of strings and subsequently extracted as a string. This would be a breach of type safety. However, there are certain interfaces where the above cannot occur, notably where there is no way to insert an object into the collection. Such an interface is IEnumerable<T>. If instead you say: IEnumerable<object> objects = strings; There is no way we can put the wrong kind of thing into strings through objects, because objects doesn’t have a method that takes an element in. Variance is about allowing assignments such as this in cases where it is safe. The result is that a lot of situations that were previously surprising now just work. Covariance In .NET 4.0 the IEnumerable<T> interface will be declared in the following way: public interface IEnumerable<out T> : IEnumerable { IEnumerator<T> GetEnumerator(); } public interface IEnumerator<out T> : IEnumerator { bool MoveNext(); T Current { get; } } The “out” in these declarations signifies that the T can only occur in output position in the interface – the compiler will complain otherwise. In return for this restriction, the interface becomes “covariant” in T, which means that an IEnumerable<A> is considered an IEnumerable<B> if A has a reference conversion to B. As a result, any sequence of strings is also e.g. a sequence of objects. This is useful e.g. in many LINQ methods. Using the declarations above: var result = strings.Union(objects); // succeeds with an IEnumerable<object> This would previously have been disallowed, and you would have had to to some cumbersome wrapping to get the two sequences to have the same element type. Contravariance Type parameters can also have an “in” modifier, restricting them to occur only in input positions. An example is IComparer<T>: public interface IComparer<in T> { public int Compare(T left, T right); } The somewhat baffling result is that an IComparer<object> can in fact be considered an IComparer<string>! It makes sense when you think about it: If a comparer can compare any two objects, it can certainly also compare two strings. This property is referred to as contravariance. A generic type can have both in and out modifiers on its type parameters, as is the case with the Func<…> delegate types: public delegate TResult Func<in TArg, out TResult>(TArg arg); Obviously the argument only ever comes in, and the result only ever comes out. Therefore a Func<object,string> can in fact be used as a Func<string,object>. Limitations Variant type parameters can only be declared on interfaces and delegate types, due to a restriction in the CLR. Variance only applies when there is a reference conversion between the type arguments. For instance, an IEnumerable<int> is not an IEnumerable<object> because the conversion from int to object is a boxing conversion, not a reference conversion. Also please note that the CTP does not contain the new versions of the .NET types mentioned above. In order to experiment with variance you have to declare your own variant interfaces and delegate types. COM Example Here is a larger Office automation example that shows many of the new C# features in action. using System; using System.Diagnostics; using System.Linq; using Excel = Microsoft.Office.Interop.Excel; using Word = Microsoft.Office.Interop.Word; class Program { static void Main(string[] args) { var excel = new Excel.Application(); excel.Visible = true; excel.Workbooks.Add(); // optional arguments omitted excel.Cells[1, 1].Value = "Process Name"; // no casts; Value dynamically excel.Cells[1, 2].Value = "Memory Usage"; // accessed var processes = Process.GetProcesses() .OrderByDescending(p =&gt; p.WorkingSet) .Take(10); int i = 2; foreach (var p in processes) { excel.Cells[i, 1].Value = p.ProcessName; // no casts excel.Cells[i, 2].Value = p.WorkingSet; // no casts i++; } Excel.Range range = excel.Cells[1, 1]; // no casts Excel.Chart chart = excel.ActiveWorkbook.Charts. Add(After: excel.ActiveSheet); // named and optional arguments chart.ChartWizard( Source: range.CurrentRegion, Title: "Memory Usage in " + Environment.MachineName); //named+optional chart.ChartStyle = 45; chart.CopyPicture(Excel.XlPictureAppearance.xlScreen, Excel.XlCopyPictureFormat.xlBitmap, Excel.XlPictureAppearance.xlScreen); var word = new Word.Application(); word.Visible = true; word.Documents.Add(); // optional arguments word.Selection.Paste(); } } The code is much more terse and readable than the C# 3.0 counterpart. Note especially how the Value property is accessed dynamically. This is actually an indexed property, i.e. a property that takes an argument; something which C# does not understand. However the argument is optional. Since the access is dynamic, it goes through the runtime COM binder which knows to substitute the default value and call the indexed property. Thus, dynamic COM allows you to avoid accesses to the puzzling Value2 property of Excel ranges. Relationship with Visual Basic A number of the features introduced to C# 4.0 already exist or will be introduced in some form or other in Visual Basic: · Late binding in VB is similar in many ways to dynamic lookup in C#, and can be expected to make more use of the DLR in the future, leading to further parity with C#. · Named and optional arguments have been part of Visual Basic for a long time, and the C# version of the feature is explicitly engineered with maximal VB interoperability in mind. · NoPIA and variance are both being introduced to VB and C# at the same time. VB in turn is adding a number of features that have hitherto been a mainstay of C#. As a result future versions of C# and VB will have much better feature parity, for the benefit of everyone. Resources All available resources concerning C# 4.0 can be accessed through the C# Dev Center. Specifically, this white paper and other resources can be found at the Code Gallery site. Enjoy! span.fullpost {display:none;}

    Read the article

  • .Net to Oracle Connectivity using ODBC .NET

    - by SAMIR BHOGAYTA
    You can use the new ODBC .NET Data Provider that works with the ODBC Oracle7.x driver or higher. You need to have MDAC 2.6 or later installed and then download ODBC .NET from the MS Web Site http://msdn.microsoft.com/downloads/default.asp?url=/code/sample.asp?url=/msdn-files/027/001/668/msdncompositedoc.xml&frame=true. MDAC (Microsoft Data Access Component) 2.7 contains core component, including the Microsoft SQL server and Oracle OLE Database provider and ODBC driver. Insta ...You can use the new ODBC .NET Data Provider that works with the ODBC Oracle7.x driver or higher. You need to have MDAC 2.6 or later installed and then download ODBC .NET from the MS Web Site http://msdn.microsoft.com/downloads/default.asp?url=/code/sample.asp?url=/msdn-files/027/001/668/msdncompositedoc.xml&frame=true. MDAC (Microsoft Data Access Component) 2.7 contains core component, including the Microsoft SQL server and Oracle OLE Database provider and ODBC driver. Install ODBC .NET from the MS Web Site http://msdn.microsoft.com/downloads/default.asp?URL=/downloads/sample.asp?url=/msdn-files/027/001/943/msdncompositedoc.xml Create a DSN, using either Microsoft ODBC for Oracle or Oracle supplied Driver if the Oracle client software is loaded. here for eq. TrailDSN. While creating DSN give user name along with passward for eq. scott/tiger. using Microsoft .Data.Odbc; private void Form1_Load(object sender, System.EventArgs e) { try { OdbcConnection myconnection= new OdbcConnection ("DSN=TrialDSN"); OdbcDataAdapter myda = new OdbcDataAdapter ("Select * from EMP", myconnection); DataSet ds= new DataSet (); myda.Fill(ds, "Table"); dataGrid1.DataSource = ds ; } catch(Exception ex) { MessageBox.Show (ex.Message ); } }

    Read the article

  • Coexistence of projects between Visual Studio 2010 and 2012

    - by sreejukg
    Microsoft has released another version of Visual Studio named Visual Studio 2012. As you can see there are user interface (UI) changes in all/most of the Microsoft applications as Microsoft is moving towards Windows 8 and changing the UI scheme for all of the applications. Visual Studio 2012 is a move to adapt the new interface requirements that are in coherent with Windows 8. Not only this Visual Studio 2012 has lots of improvements in several areas and it supports .Net framework 4.5. In the past, whenever a new version of Visual Studio launches, developers needed to upgrade the project to new version of Visual Studio which was a pain, especially when you are working with a team of developers. Once a solution is upgraded to a newer version, it was not possible to going back. With Visual studio 2012, you can avoid the pain of upgrading. Developers will be able to open their project in Visual Studio 2012 along with Visual Studio 2010 SP 1. This means if you create a project using Visual Studio 2012, you will be able to open it with Visual Studio 2010 SP 1 and vice versa. There are some exceptions (as always!). Visual Studio 2012 supports some new project types, which was not there in 2010 version. Such project, you will not be able to open in Visual Studio 2010. For e.g. Visual Studio 2012 brings a new project type named “Windows 8 Modern Applications”, such projects you will not be able to open using the 2010 version of Visual Studio. Just to prove the said subject, I am going to perform some simple operations. I installed Visual Studio 2010 with SP 1 and Visual Studio 2012 on my PC. See the snapshots for both the installations. Visual Studio 2010 Visual Studio 2012 Now I am going to perform two test cases. First create a project in 2010 Version and open it in 2012 version and vice versa. If you are interested, you can continue scrolling down, otherwise just say bye bye to this article. Case 1: Open a solution created using Visual Studio 2010 in 2012 version. I created a project in VS 2010 named TestProject2010 using empty ASP.Net web application template. Once created the project appears in VS 2010 as follows. I closed Visual Studio and opened the solution file using VS 2012 by using the Open Project dialog(File -> Open Project/Solution). Surprisingly, there is not even a warning message, just the project opened fine in Visual Studio 2012. Case 2: Open a solution created using Visual Studio 2012 in 2010 version. I have created a project in Visual Studio 2012 named testProject2012. See the screenshot of the project in VS 2012 below. Now try opening the solution in Visual Studio 2010. The solution loaded successfully, but Visual Studio failed to load project. See the screenshot. At first I was surprised. The Web application project template is available in both versions, So there should not be any problem. What is making the incompatibility? Is it ASP.Net version? Yes it is. VS 2012 assign ASP.Net 4.5 as the default version that was causing the trouble for Visual Studio 2010. I changed the version to .Net framework 4.0 and saved the project after that I was able to open the project in Visual Studio 2010. This as an excellent move from Visual Studio Team and allows enterprises to perform gradual upgrade to the new version. Now developers can work in any version based on availability and preference, simply I can use Visual Studio 2012 as my IDE while my colleague working on the same project can still use Visual Studio 2010.

    Read the article

  • Developing web apps using ASP.NET MVC 3, Razor and EF Code First - Part 2

    - by shiju
    In my previous post Developing web apps using ASP.NET MVC 3, Razor and EF Code First - Part 1, we have discussed on how to work with ASP.NET MVC 3 and EF Code First for developing web apps. We have created generic repository and unit of work with EF Code First for our ASP.NET MVC 3 application and did basic CRUD operations against a simple domain entity. In this post, I will demonstrate on working with domain entity with deep object graph, Service Layer and View Models and will also complete the rest of the demo application. In the previous post, we have done CRUD operations against Category entity and this post will be focus on Expense entity those have an association with Category entity. You can download the source code from http://efmvc.codeplex.com . The following frameworks will be used for this step by step tutorial.    1. ASP.NET MVC 3 RTM    2. EF Code First CTP 5    3. Unity 2.0 Domain Model Category Entity public class Category   {       public int CategoryId { get; set; }       [Required(ErrorMessage = "Name Required")]       [StringLength(25, ErrorMessage = "Must be less than 25 characters")]       public string Name { get; set;}       public string Description { get; set; }       public virtual ICollection<Expense> Expenses { get; set; }   } Expense Entity public class Expense     {                public int ExpenseId { get; set; }                public string  Transaction { get; set; }         public DateTime Date { get; set; }         public double Amount { get; set; }         public int CategoryId { get; set; }         public virtual Category Category { get; set; }     } We have two domain entities - Category and Expense. A single category contains a list of expense transactions and every expense transaction should have a Category. Repository class for Expense Transaction Let’s create repository class for handling CRUD operations for Expense entity public class ExpenseRepository : RepositoryBase<Expense>, IExpenseRepository     {     public ExpenseRepository(IDatabaseFactory databaseFactory)         : base(databaseFactory)         {         }                } public interface IExpenseRepository : IRepository<Expense> { } Service Layer If you are new to Service Layer, checkout Martin Fowler's article Service Layer . According to Martin Fowler, Service Layer defines an application's boundary and its set of available operations from the perspective of interfacing client layers. It encapsulates the application's business logic, controlling transactions and coordinating responses in the implementation of its operations. Controller classes should be lightweight and do not put much of business logic onto it. We can use the service layer as the business logic layer and can encapsulate the rules of the application. Let’s create a Service class for coordinates the transaction for Expense public interface IExpenseService {     IEnumerable<Expense> GetExpenses(DateTime startDate, DateTime ednDate);     Expense GetExpense(int id);             void CreateExpense(Expense expense);     void DeleteExpense(int id);     void SaveExpense(); } public class ExpenseService : IExpenseService {     private readonly IExpenseRepository expenseRepository;            private readonly IUnitOfWork unitOfWork;     public ExpenseService(IExpenseRepository expenseRepository, IUnitOfWork unitOfWork)     {                  this.expenseRepository = expenseRepository;         this.unitOfWork = unitOfWork;     }     public IEnumerable<Expense> GetExpenses(DateTime startDate, DateTime endDate)     {         var expenses = expenseRepository.GetMany(exp => exp.Date >= startDate && exp.Date <= endDate);         return expenses;     }     public void CreateExpense(Expense expense)     {         expenseRepository.Add(expense);         unitOfWork.Commit();     }     public Expense GetExpense(int id)     {         var expense = expenseRepository.GetById(id);         return expense;     }     public void DeleteExpense(int id)     {         var expense = expenseRepository.GetById(id);         expenseRepository.Delete(expense);         unitOfWork.Commit();     }     public void SaveExpense()     {         unitOfWork.Commit();     } }   View Model for Expense Transactions In real world ASP.NET MVC applications, we need to design model objects especially for our views. Our domain objects are mainly designed for the needs for domain model and it is representing the domain of our applications. On the other hand, View Model objects are designed for our needs for views. We have an Expense domain entity that has an association with Category. While we are creating a new Expense, we have to specify that in which Category belongs with the new Expense transaction. The user interface for Expense transaction will have form fields for representing the Expense entity and a CategoryId for representing the Category. So let's create view model for representing the need for Expense transactions. public class ExpenseViewModel {     public int ExpenseId { get; set; }       [Required(ErrorMessage = "Category Required")]     public int CategoryId { get; set; }       [Required(ErrorMessage = "Transaction Required")]     public string Transaction { get; set; }       [Required(ErrorMessage = "Date Required")]     public DateTime Date { get; set; }       [Required(ErrorMessage = "Amount Required")]     public double Amount { get; set; }       public IEnumerable<SelectListItem> Category { get; set; } } The ExpenseViewModel is designed for the purpose of View template and contains the all validation rules. It has properties for mapping values to Expense entity and a property Category for binding values to a drop-down for list values of Category. Create Expense transaction Let’s create action methods in the ExpenseController for creating expense transactions public ActionResult Create() {     var expenseModel = new ExpenseViewModel();     var categories = categoryService.GetCategories();     expenseModel.Category = categories.ToSelectListItems(-1);     expenseModel.Date = DateTime.Today;     return View(expenseModel); } [HttpPost] public ActionResult Create(ExpenseViewModel expenseViewModel) {                      if (!ModelState.IsValid)         {             var categories = categoryService.GetCategories();             expenseViewModel.Category = categories.ToSelectListItems(expenseViewModel.CategoryId);             return View("Save", expenseViewModel);         }         Expense expense=new Expense();         ModelCopier.CopyModel(expenseViewModel,expense);         expenseService.CreateExpense(expense);         return RedirectToAction("Index");              } In the Create action method for HttpGet request, we have created an instance of our View Model ExpenseViewModel with Category information for the drop-down list and passing the Model object to View template. The extension method ToSelectListItems is shown below   public static IEnumerable<SelectListItem> ToSelectListItems(         this IEnumerable<Category> categories, int  selectedId) {     return           categories.OrderBy(category => category.Name)                 .Select(category =>                     new SelectListItem                     {                         Selected = (category.CategoryId == selectedId),                         Text = category.Name,                         Value = category.CategoryId.ToString()                     }); } In the Create action method for HttpPost, our view model object ExpenseViewModel will map with posted form input values. We need to create an instance of Expense for the persistence purpose. So we need to copy values from ExpenseViewModel object to Expense object. ASP.NET MVC futures assembly provides a static class ModelCopier that can use for copying values between Model objects. ModelCopier class has two static methods - CopyCollection and CopyModel.CopyCollection method will copy values between two collection objects and CopyModel will copy values between two model objects. We have used CopyModel method of ModelCopier class for copying values from expenseViewModel object to expense object. Finally we did a call to CreateExpense method of ExpenseService class for persisting new expense transaction. List Expense Transactions We want to list expense transactions based on a date range. So let’s create action method for filtering expense transactions with a specified date range. public ActionResult Index(DateTime? startDate, DateTime? endDate) {     //If date is not passed, take current month's first and last dte     DateTime dtNow;     dtNow = DateTime.Today;     if (!startDate.HasValue)     {         startDate = new DateTime(dtNow.Year, dtNow.Month, 1);         endDate = startDate.Value.AddMonths(1).AddDays(-1);     }     //take last date of start date's month, if end date is not passed     if (startDate.HasValue && !endDate.HasValue)     {         endDate = (new DateTime(startDate.Value.Year, startDate.Value.Month, 1)).AddMonths(1).AddDays(-1);     }     var expenses = expenseService.GetExpenses(startDate.Value ,endDate.Value);     //if request is Ajax will return partial view     if (Request.IsAjaxRequest())     {         return PartialView("ExpenseList", expenses);     }     //set start date and end date to ViewBag dictionary     ViewBag.StartDate = startDate.Value.ToShortDateString();     ViewBag.EndDate = endDate.Value.ToShortDateString();     //if request is not ajax     return View(expenses); } We are using the above Index Action method for both Ajax requests and normal requests. If there is a request for Ajax, we will call the PartialView ExpenseList. Razor Views for listing Expense information Let’s create view templates in Razor for showing list of Expense information ExpenseList.cshtml @model IEnumerable<MyFinance.Domain.Expense>   <table>         <tr>             <th>Actions</th>             <th>Category</th>             <th>                 Transaction             </th>             <th>                 Date             </th>             <th>                 Amount             </th>         </tr>       @foreach (var item in Model) {              <tr>             <td>                 @Html.ActionLink("Edit", "Edit",new { id = item.ExpenseId })                 @Ajax.ActionLink("Delete", "Delete", new { id = item.ExpenseId }, new AjaxOptions { Confirm = "Delete Expense?", HttpMethod = "Post", UpdateTargetId = "divExpenseList" })             </td>              <td>                 @item.Category.Name             </td>             <td>                 @item.Transaction             </td>             <td>                 @String.Format("{0:d}", item.Date)             </td>             <td>                 @String.Format("{0:F}", item.Amount)             </td>         </tr>          }       </table>     <p>         @Html.ActionLink("Create New Expense", "Create") |         @Html.ActionLink("Create New Category", "Create","Category")     </p> Index.cshtml @using MyFinance.Helpers; @model IEnumerable<MyFinance.Domain.Expense> @{     ViewBag.Title = "Index"; }    <h2>Expense List</h2>    <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery-ui.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.ui.datepicker.js")" type="text/javascript"></script> <link href="@Url.Content("~/Content/jquery-ui-1.8.6.custom.css")" rel="stylesheet" type="text/css" />      @using (Ajax.BeginForm(new AjaxOptions{ UpdateTargetId="divExpenseList", HttpMethod="Get"})) {     <table>         <tr>         <td>         <div>           Start Date: @Html.TextBox("StartDate", Html.Encode(String.Format("{0:mm/dd/yyyy}", ViewData["StartDate"].ToString())), new { @class = "ui-datepicker" })         </div>         </td>         <td><div>            End Date: @Html.TextBox("EndDate", Html.Encode(String.Format("{0:mm/dd/yyyy}", ViewData["EndDate"].ToString())), new { @class = "ui-datepicker" })          </div></td>          <td> <input type="submit" value="Search By TransactionDate" /></td>         </tr>     </table>         }   <div id="divExpenseList">             @Html.Partial("ExpenseList", Model)     </div> <script type="text/javascript">     $().ready(function () {         $('.ui-datepicker').datepicker({             dateFormat: 'mm/dd/yy',             buttonImage: '@Url.Content("~/Content/calendar.gif")',             buttonImageOnly: true,             showOn: "button"         });     }); </script> Ajax search functionality using Ajax.BeginForm The search functionality of Index view is providing Ajax functionality using Ajax.BeginForm. The Ajax.BeginForm() method writes an opening <form> tag to the response. You can use this method in a using block. In that case, the method renders the closing </form> tag at the end of the using block and the form is submitted asynchronously by using JavaScript. The search functionality will call the Index Action method and this will return partial view ExpenseList for updating the search result. We want to update the response UI for the Ajax request onto divExpenseList element. So we have specified the UpdateTargetId as "divExpenseList" in the Ajax.BeginForm method. Add jQuery DatePicker Our search functionality is using a date range so we are providing two date pickers using jQuery datepicker. You need to add reference to the following JavaScript files to working with jQuery datepicker. jquery-ui.js jquery.ui.datepicker.js For theme support for datepicker, we can use a customized CSS class. In our example we have used a CSS file “jquery-ui-1.8.6.custom.css”. For more details about the datepicker component, visit jquery UI website at http://jqueryui.com/demos/datepicker . In the jQuery ready event, we have used following JavaScript function to initialize the UI element to show date picker. <script type="text/javascript">     $().ready(function () {         $('.ui-datepicker').datepicker({             dateFormat: 'mm/dd/yy',             buttonImage: '@Url.Content("~/Content/calendar.gif")',             buttonImageOnly: true,             showOn: "button"         });     }); </script>   Source Code You can download the source code from http://efmvc.codeplex.com/ . Summary In this two-part series, we have created a simple web application using ASP.NET MVC 3 RTM, Razor and EF Code First CTP 5. I have demonstrated patterns and practices  such as Dependency Injection, Repository pattern, Unit of Work, ViewModel and Service Layer. My primary objective was to demonstrate different practices and options for developing web apps using ASP.NET MVC 3 and EF Code First. You can implement these approaches in your own way for building web apps using ASP.NET MVC 3. I will refactor this demo app on later time.

    Read the article

  • ASP.NET MVC 3 SERIES

    - by carlone
      Estimados Lectores,   Luego de un tiempo ausente en mi blog, re-tomamos el rumbo… en esta oportunidad quiero comunicarles que iniciaré una serie de screencast sobre ASP.NET MVC, en donde me estare enfocando desde los conceptos básicos del patrón, pasaremos por las definiciones y conceptos utilizados dentro del ASP.NET MVC para la Vista, El controlador y el Modelo.   Estos videos tengo pensados que sean cápsulas no mayores a los 10 minutos para que sean fáciles de entender y visualizar.   Para los que quieran prepararse con tiempo les recomiendo descargar las tools requeridas para esta series-curso:   Descargar los tools de ASP.NET MVC 3 para VS2010: http://www.microsoft.com/en-us/download/details.aspx?id=1491 , seleccionar el archivo “AspNetMVC3ToolsUpdateSetup.exe” (Nota: si tienen el web platform installer también pueden instalar desde esta tool el ASP.NET MVC 3)   Recuerden que pueden utilizar el Web Developer Express 2010 también para el desarrollo:  mi recomendación es que lo hagan por medio del Web Platform Installer:  Install Visual Web Developer Express Free   Bueno esten pendientes de los próximos videos que estaré publicando.   Cualquier comentario o sugerencia es bienvenido!   Saludos   Carlos A. Lone

    Read the article

  • Running ASP.NET Webforms and ASP.NET MVC side by side

    - by rajbk
    One of the nice things about ASP.NET MVC and its older brother ASP.NET WebForms is that they are both built on top of the ASP.NET runtime environment. The advantage of this is that, you can still run them side by side even though MVC and WebForms are different frameworks. Another point to note is that with the release of the ASP.NET routing in .NET 3.5 SP1, we are able to create SEO friendly URLs that do not map to specific files on disk. The routing is part of the core runtime environment and therefore can be used by both WebForms and MVC. To run both frameworks side by side, we could easily create a separate folder in your MVC project for all our WebForm files and be good to go. What this post shows you instead, is how to have an MVC application with WebForm pages  that both use a common master page and common routing for SEO friendly URLs.  A sample project that shows WebForms and MVC running side by side is attached at the bottom of this post. So why would we want to run WebForms and MVC in the same project?  WebForms come with a lot of nice server controls that provide a lot of functionality. One example is the ReportViewer control. Using this control and client report definition files (RDLC), we can create rich interactive reports (with charting controls). I show you how to use the ReportViewer control in a WebForm project here :  Creating an ASP.NET report using Visual Studio 2010. We can create even more advanced reports by using SQL reporting services that can also be rendered by the ReportViewer control. Now, consider the sample MVC application I blogged about called ASP.NET MVC Paging/Sorting/Filtering using the MVCContrib Grid and Pager. Assume you were given the requirement to add a UI to the MVC application where users could interact with a report and be given the option to export the report to Excel, PDF or Word. How do you go about doing it?   This is a perfect scenario to use the ReportViewer control and RDLCs. As you saw in the post on creating the ASP.NET report, the ReportViewer control is a Web Control and is designed to be run in a WebForm project with dependencies on, amongst others, a ScriptManager control and the beloved Viewstate.  Since MVC and WebForm both run under the same runtime, the easiest thing to is to add the WebForm application files (index.aspx, rdlc, related class files) into our MVC project. You can copy the files over from the WebForm project into the MVC project. Create a new folder in our MVC application called CommonReports. Add the index.aspx and rdlc file from the Webform project   Right click on the Index.aspx file and convert it to a web application. This will add the index.aspx.designer.cs file (this step is not required if you are manually adding a WebForm aspx file into the MVC project).    Verify that all the type names for the ObjectDataSources in code behind to point to the correct ProductRepository and fix any compiler errors. Right click on Index.aspx and select “View in browser”. You should see a screen like the one below:   There are two issues with our page. It does not use our site master page and the URL is not SEO friendly. Common Master Page The easiest way to use master pages with both MVC and WebForm pages is to have a common master page that each inherits from as shown below. The reason for this is most WebForm controls require them to be inside a Form control and require ControlState or ViewState. ViewMasterPages used in MVC, on the other hand, are designed to be used with content pages that derive from ViewPage with Viewstate turned off. By having a separate master page for MVC and WebForm that inherit from the Root master page,, we can set properties that are specific to each. For example, in the Webform master, we can turn on ViewState, add a form tag etc. Another point worth noting is that if you set a WebForm page to use a MVC site master page, you may run into errors like the following: A ViewMasterPage can be used only with content pages that derive from ViewPage or ViewPage<TViewItem> or Control 'MainContent_MyButton' of type 'Button' must be placed inside a form tag with runat=server. Since the ViewMasterPage inherits from MasterPage as seen below, we make our Root.master inherit from MasterPage, MVC.master inherit from ViewMasterPage and Webform.master inherits from MasterPage. We define the attributes on the master pages like so: Root.master <%@ Master Inherits="System.Web.UI.MasterPage"  … %> MVC.master <%@ Master MasterPageFile="~/Views/Shared/Root.Master" Inherits="System.Web.Mvc.ViewMasterPage" … %> WebForm.master <%@ Master MasterPageFile="~/Views/Shared/Root.Master" Inherits="NorthwindSales.Views.Shared.Webform" %> Code behind: public partial class Webform : System.Web.UI.MasterPage {} We make changes to our reports aspx file to use the Webform.master. See the source of the master pages in the sample project for a better understanding of how they are connected. SEO friendly links We want to create SEO friendly links that point to our report. A request to /Reports/Products should render the report located in ~/CommonReports/Products.aspx. Simillarly to support future reports, a request to /Reports/Sales should render a report in ~/CommonReports/Sales.aspx. Lets start by renaming our index.aspx file to Products.aspx to be consistent with our routing criteria above. As mentioned earlier, since routing is part of the core runtime environment, we ca easily create a custom route for our reports by adding an entry in Global.asax. public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}");   //Custom route for reports routes.MapPageRoute( "ReportRoute", // Route name "Reports/{reportname}", // URL "~/CommonReports/{reportname}.aspx" // File );     routes.MapRoute( "Default", // Route name "{controller}/{action}/{id}", // URL with parameters new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults ); } With our custom route in place, a request to Reports/Employees will render the page at ~/CommonReports/Employees.aspx. We make this custom route the first entry since the routing system walks the table from top to bottom, and the first route to match wins. Note that it is highly recommended that you write unit tests for your routes to ensure that the mappings you defined are correct. Common Menu Structure The master page in our original MVC project had a menu structure like so: <ul id="menu"> <li> <%=Html.ActionLink("Home", "Index", "Home") %></li> <li> <%=Html.ActionLink("Products", "Index", "Products") %></li> <li> <%=Html.ActionLink("Help", "Help", "Home") %></li> </ul> We want this menu structure to be common to all pages/views and hence should reside in Root.master. Unfortunately the Html.ActionLink helpers will not work since Root.master inherits from MasterPage which does not have the helper methods available. The quickest way to resolve this issue is to use RouteUrl expressions. Using  RouteUrl expressions, we can programmatically generate URLs that are based on route definitions. By specifying parameter values and a route name if required, we get back a URL string that corresponds to a matching route. We move our menu structure to Root.master and change it to use RouteUrl expressions: <ul id="menu"> <li> <asp:HyperLink ID="hypHome" runat="server" NavigateUrl="<%$RouteUrl:routename=default,controller=home,action=index%>">Home</asp:HyperLink></li> <li> <asp:HyperLink ID="hypProducts" runat="server" NavigateUrl="<%$RouteUrl:routename=default,controller=products,action=index%>">Products</asp:HyperLink></li> <li> <asp:HyperLink ID="hypReport" runat="server" NavigateUrl="<%$RouteUrl:routename=ReportRoute,reportname=products%>">Product Report</asp:HyperLink></li> <li> <asp:HyperLink ID="hypHelp" runat="server" NavigateUrl="<%$RouteUrl:routename=default,controller=home,action=help%>">Help</asp:HyperLink></li> </ul> We are done adding the common navigation to our application. The application now uses a common theme, routing and navigation structure. Conclusion We have seen how to do the following through this post Add a WebForm page from a WebForm project to an existing ASP.NET MVC application Use a common master page for both WebForm and MVC pages Use routing for SEO friendly links Use a common menu structure for both WebForm and MVC. The sample project is attached below. Version: VS 2010 RTM Remember to change your connection string to point to your Northwind database NorthwindSalesMVCWebform.zip

    Read the article

  • New <%: %> Syntax for HTML Encoding Output in ASP.NET 4 (and ASP.NET MVC 2)

    - by ScottGu
    [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] This is the nineteenth in a series of blog posts I’m doing on the upcoming VS 2010 and .NET 4 release. Today’s post covers a small, but very useful, new syntax feature being introduced with ASP.NET 4 – which is the ability to automatically HTML encode output within code nuggets.  This helps protect your applications and sites against cross-site script injection (XSS) and HTML injection attacks, and enables you to do so using a nice concise syntax. HTML Encoding Cross-site script injection (XSS) and HTML encoding attacks are two of the most common security issues that plague web-sites and applications.  They occur when hackers find a way to inject client-side script or HTML markup into web-pages that are then viewed by other visitors to a site.  This can be used to both vandalize a site, as well as enable hackers to run client-script code that steals cookie data and/or exploits a user’s identity on a site to do bad things. One way to help mitigate against cross-site scripting attacks is to make sure that rendered output is HTML encoded within a page.  This helps ensures that any content that might have been input/modified by an end-user cannot be output back onto a page containing tags like <script> or <img> elements.  ASP.NET applications (especially those using ASP.NET MVC) often rely on using <%= %> code-nugget expressions to render output.  Developers today often use the Server.HtmlEncode() or HttpUtility.Encode() helper methods within these expressions to HTML encode the output before it is rendered.  This can be done using code like below: While this works fine, there are two downsides of it: It is a little verbose Developers often forget to call the HtmlEncode method New <%: %> Code Nugget Syntax With ASP.NET 4 we are introducing a new code expression syntax (<%:  %>) that renders output like <%= %> blocks do – but which also automatically HTML encodes it before doing so.  This eliminates the need to explicitly HTML encode content like we did in the example above.  Instead you can just write the more concise code below to accomplish the same thing: We chose the <%: %> syntax so that it would be easy to quickly replace existing instances of <%= %> code blocks.  It also enables you to easily search your code-base for <%= %> elements to find and verify any cases where you are not using HTML encoding within your application to ensure that you have the correct behavior. Avoiding Double Encoding While HTML encoding content is often a good best practice, there are times when the content you are outputting is meant to be HTML or is already encoded – in which case you don’t want to HTML encode it again.  ASP.NET 4 introduces a new IHtmlString interface (along with a concrete implementation: HtmlString) that you can implement on types to indicate that its value is already properly encoded (or otherwise examined) for displaying as HTML, and that therefore the value should not be HTML-encoded again.  The <%: %> code-nugget syntax checks for the presence of the IHtmlString interface and will not HTML encode the output of the code expression if its value implements this interface.  This allows developers to avoid having to decide on a per-case basis whether to use <%= %> or <%: %> code-nuggets.  Instead you can always use <%: %> code nuggets, and then have any properties or data-types that are already HTML encoded implement the IHtmlString interface. Using ASP.NET MVC HTML Helper Methods with <%: %> For a practical example of where this HTML encoding escape mechanism is useful, consider scenarios where you use HTML helper methods with ASP.NET MVC.  These helper methods typically return HTML.  For example: the Html.TextBox() helper method returns markup like <input type=”text”/>.  With ASP.NET MVC 2 these helper methods now by default return HtmlString types – which indicates that the returned string content is safe for rendering and should not be encoded by <%: %> nuggets.  This allows you to use these methods within both <%= %> code nugget blocks: As well as within <%: %> code nugget blocks: In both cases above the HTML content returned from the helper method will be rendered to the client as HTML – and the <%: %> code nugget will avoid double-encoding it. This enables you to default to always using <%: %> code nuggets instead of <%= %> code blocks within your applications.  If you want to be really hardcore you can even create a build rule that searches your application looking for <%= %> usages and flags any cases it finds as an error to enforce that HTML encoding always takes place. Scaffolding ASP.NET MVC 2 Views When you use VS 2010 (or the free Visual Web Developer 2010 Express) you’ll find that the views that are scaffolded using the “Add View” dialog now by default always use <%: %> blocks when outputting any content.  For example, below I’ve scaffolded a simple “Edit” view for an article object.  Note the three usages of <%: %> code nuggets for the label, textbox, and validation message (all output with HTML helper methods): Summary The new <%: %> syntax provides a concise way to automatically HTML encode content and then render it as output.  It allows you to make your code a little less verbose, and to easily check/verify that you are always HTML encoding content throughout your site.  This can help protect your applications against cross-site script injection (XSS) and HTML injection attacks.  Hope this helps, Scott

    Read the article

  • Traditional ASP.Net WebForms vs ASP.Net MVC

    - by Pankaj Upadhyay
    ASP.Net MVC has been around for some time now. The latest one, i.e MVC3 comes with Razor View Engine. My question: How long is traditional ASP.Net here to stay. Does Microsoft have any plans to eliminate it in aid of ASP.Net MVC in the future and will the next release of VS incorporate it? Also, I would like to know if there is any merit of traditional over ASP.Net MVC, other than the controls-aid?

    Read the article

  • Transposition - the success story of VB6 migration

    - by Visual WebGui
    Since all of you VB developers in the present or past would probably find it hard to believe that the old VB code can be migrated and modernized into the latest .NET based HTML5 without having to rewrite the application I am feeling I need to write another post on our migration solution. Hopefully, after reading this and the previous post you will be able to understand the different approach of our solution which already helps organizations around the world move away from the constraints of VB6 and...(read more)

    Read the article

  • Allowing asterisk in URL - ASP.NET MVC 2 - .NET 4.0 or encoding

    - by raRaRa
    I'm having a trouble allowing asterisk (*) in the URL of my website. I am running ASP.NET MVC 2 and .NET 4.0. Here's an example that describes the problem: http://mysite.com/profile/view/Nice* The username is Nice* and ASP.NET says there are illegal characters in the URL: Illegal characters in path. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.ArgumentException: Illegal characters in path. I have tried all the Web.config methods I've seen online such as: <pages validateRequest="false"> and <httpRuntime requestPathInvalidCharacters="" requestValidationMode="2.0" /> So my question is: Is it possible to allow asterisk in URL? If not, is there some encoding method in .NET that can encode asterisk(*) ? Thanks!

    Read the article

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >