Search Results

Search found 13829 results on 554 pages for 'temporary objects'.

Page 489/554 | < Previous Page | 485 486 487 488 489 490 491 492 493 494 495 496  | Next Page >

  • Scalability 101: How can I design a scalable web application using PHP?

    - by Legend
    I am building a web-application and have a couple of quick questions. From what I learnt, one should not worry about scalability when initially building the app and should only start worrying when the traffic increases. However, this being my first web-application, I am not quite sure if I should take an approach where I design things in an ad-hoc manner and later "fix" them. I have been reading stories about how people start off with an app that gets millions of users in a week or two. Not that I will face the same situation but I can't help but wonder, how do these people do it? Currently, I bought a shared hosting account on Lunarpages and that got me started in building and testing the application. However, I am interested in learning how to build the same application in a scalable-manner using the cloud, for instance, Amazon's EC2. From my understanding, I can see a couple of components: There is a load balancer that first receives requests and then decides where to route each request This request is then handled by a server replica that then processes the request and updates (if required) the database and sends back the response to the client If a similar request comes in, then a caching mechanism like memcached kicks into picture and returns objects from the cache A blackbox that handles database replication Specifically, I am trying to do the following: Setting up a load balancer (my homework revealed that HAProxy is one such load balancer) Setting up replication so that databases can be synchronized Using memcached Configuring Apache to work with multiple web servers Partitioning application to use Amazon EC2 and Amazon S3 (my application is something that will need great deal of storage) Finally, how can I avoid burning myself when using Amazon services? Because this is just a learning phase, I can probably do with 2-3 servers with a simple load balancer and replication but until I want to avoid paying loads of money accidentally. I am able to find resources on individual topics but am unable to find something that starts off from the big picture. Can someone please help me get started?

    Read the article

  • Enterprise integration of disparate systems

    - by Chris Latta
    We're about to embark on a fairly large integration effort to kill off a bunch of Access and Sql Server databases and get everything into one coherent enterprise system. There are also a number of other systems (accounting, CRM, payroll, MS Exchange) that hold critical data that we need to integrate (use for data validation in other systems), report on and otherwise expose. It is likely that some of these systems will change in the next few years, so we need to isolate our systems to be ready for change. Ideally we would be able to expose our forms in a consistent manner across as many of our our systems as possible without having to re-develop them for each system. We are currently targeting SharePoint (2007 and soon 2010), Office (2007 and soon 2010 - Word, Excel, PowerPoint and Outlook), Reporting Services, .Net console applications, .Net Windows applications, shell extensions, and with the possibility of exposing some functionality on mobile devices (BlackBerries currently, maybe iPhones later) and via our website. We're moving development to Visual Studio 2010 (from 2005) ahead of migrating to SharePoint 2010 and Office 2010. Given that most of our development is presently targeted to the .Net framework (mostly in C#) it seems logical to stick with this unless there is some compelling reason to switch frameworks/platform for some aspects. We're thinking of your standard Database-Data Integration layer-Business Objects Layer-Web Services (or REST) layer-Client Application plus doing our own client application with WPF (or something else?) forms that can also be exposed in the MS systems (SharePoint, Office, Windows). So, we don't want much, just everything :) Basically we need to isolate ourselves from database and systems changes, create an API that can be used throughout our systems and then make this functionality available in our client applications. I'm very keen to get pointers from anyone who has tips on how to pull this off. Should we look at the Enterprise Library as a place to start? Is REST with ASP.Net MVC2 a better solution than Web Services for a system like this? Will WPF deliver forms re-use or is there something better?

    Read the article

  • Linq - reuse expression on child property

    - by user175528
    Not sure if what I am trying is possible or not, but I'd like to reuse a linq expression on an objects parent property. With the given classes: class Parent { int Id { get; set; } IList<Child> Children { get; set; } string Name { get; set; } } class Child{ int Id { get; set; } Parent Dad { get; set; } string Name { get; set; } } If i then have a helper Expression<Func<Parent,bool> ParentQuery() { Expression<Func<Parent,bool> q = p => p.Name=="foo"; } I then want to use this when querying data out for a child, along the lines of: using(var context=new Entities.Context) { var data=context.Child.Where(c => c.Name=="bar" && c.Dad.Where(ParentQuery)); } I know I can do that on child collections: using(var context=new Entities.Context) { var data=context.Parent.Where(p => p.Name=="foo" && p.Childen.Where(childQuery)); } but cant see any way to do this on a property that isnt a collection. This is just a simplified example, actually the ParentQuery will be more complex and I want to avoid having this repeated in multiple places as rather than just having 2 layers I'll have closer to 5 or 6, but all of them will need to reference the parent query to ensure security.

    Read the article

  • How to manage large amounts of delegates and usercallbacks in C# async http library

    - by Tyler
    I'm coding a .NET library in C# for communicating with XBMC via its JSON RPC interface using HTTP. I coded and released a preliminary version but everything is done synchronously. I then recoded the library to be asynchronous for my own purposes as I was/am building an XBMC remote for WP7. I now want to release the new async library but want to make sure it's nice and tidy before I do. Due to the async nature a user initiates a request, supplies a callback method that matches my delegate and then handles the response once it's been received. The problem I have is that within the library I track a RequestState object for the lifetime of the request, it contains the http request/response as well as the user callback etc. as member variables, this would be fine if only one type of object was coming back but depending on what the user calls they may be returned a list of songs or a list of movies etc. My implementation at the moment uses a single delegate ResponseDataRecieved which has a single parameter which is a simple Object - As this has only be used by me I know which methods return what and when I handle the response I cast said object to the type I know it really is - List, List etc. A third party shouldn't have to do this though - The delegate signature should contain the correct type of object. So then I need a delegate for every type of response data that can be returned to the third party - The specific problem is, how do I handle this gracefully internally - Do I have a bunch of different RequestState objects that each have a different member variable for the different delegates? That doesn't "feel" right. I just don't know how to do this gracefully and cleanly.

    Read the article

  • "Invalid Object Format Name" in Crystal Reports

    - by cmays90
    When working with Crystal Report Field Objects and attempting to set "EnableSuppress" to False or alter the position or width of a field object is generating an "Invalid Object Format Name" error. The debugger shows all my code running without error until attempting to actually load the report. At that point, it will run the first couple without problem, then it fails when messing with a field object, and none of the rest will run. The code is shown below. Everything that generates an error is a FieldObject, but not all fieldObjects generate errors. In the code below, everything in Section2 is a TextObject and everything in Section3 is a FieldObject. If condition = True Then 'Lines marked as runs ok, only run when a line that generates an error is not present before it. Report.Section2.ReportObjects("Text7").Left = 7830 'Runs ok Report.Section3.ReportObjects("Field4").Left = 8085 'Runs ok Report.Section2.ReportObjects("Text13").ObjectFormat.EnableSuppress = False 'Runs ok Report.Section3.ReportObjects("Field28").ObjectFormat.EnableSuppress = False 'error Report.Section2.ReportObjects("Text9").Left = 10830 'Runs ok Report.Section3.ReportObjects("Field23").Left = 10830 'error Report.Section3.ReportObjects("Field23").Width = 615 'error Report.Section2.ReportObjects("Text10").Left = 11445 'Runs ok Report.Section3.ReportObjects("Field25").Left = 11445 'Runs ok End If

    Read the article

  • List<T> paging asp.net

    - by user1397978
    Using a three-tier architecture, I have a list of objects List<object> careerList = new List<object>(); ModuleDTO module = new ModuleDTO(); careerList = module.getDegreeCodeByQualification(qualificationCode); which I then add to a gridview like so: gridViewMaster.DataSource = careerList; gridViewMaster.DataBind(); What I'd like to do is then enable paging on the gridview. My gridview so far is: <asp:GridView ID="gridViewMaster" runat="server" AutoGenerateColumns="False" GridLines="None" BorderWidth="1px" CellPadding="2" DataKeyNames="Grouping" ForeColor="Black" onrowdatabound="gridViewMaster_RowDataBound" CssClass="mGrid" PagerStyle-CssClass="pgr" AlternatingRowStyle-CssClass="alt" OnPageIndexChanging="gridView_PageIndexChanging" AllowPaging="True" > Is it possible to do enable paging on a list's without having to change that list to a Datatable or Dataview? If there is a way, this would help a lot. So far my events are as follows: protected void gridView_PageIndexChanging(object sender, GridViewPageEventArgs e) { gridViewMaster.PageIndex = e.NewPageIndex; List<object> careerList = new List<object>(); ModuleDTO module = new ModuleDTO(); careerList = module.getDegreeCodeByQualification(qualificationCode); ModalProgress.Show(); System.Threading.Thread.Sleep(1000); JobPanel.Visible = true; gridViewMaster.DataSource = careerList.Distinct(); gridViewMaster.DataBind(); } Someone PLEASE HELP ME!!! Thank you

    Read the article

  • Business Tier | client state in desktop application- way around Stateful Session Beans?

    - by arthur
    I read positive inputs on the following posts concerning client state management: Stateful EJBs in web application?, here, and here. I want to know how implement such client state management for desktop applications (Swing, AWT, SWT, and other). let's assume there are n desktop clients supposed to use some (remote) services provided on an Application Server. How to maintain a separate and permanent data state for each client , distinct from the other without have to use using stateful session Beans (SFSB) ? is that even possible on this application type ? With Webapp(Servlets / JsSF and JSP) some can avoid using SFSB by HttpSession object and/or coupling it with stateless session beans (SLSB). HttpSession object would keep information for each (Web)client separate and the SLSB would play the business logic music. But HttpSession objects aren't present on desktop application and I go stuck with only SFSB and SLSB. Knowing the problems(Concurrency, Error Handling, usw ) of SFSB, I would have not wanted to use it. What would be the other options? is there only SFSB available? Thanks in advances

    Read the article

  • Advice on Linq to SQL mapping object design

    - by fearofawhackplanet
    I hope the title and following text are clear, I'm not very familiar with the correct terms so please correct me if I get anything wrong. I'm using Linq ORM for the first time and am wondering how to address the following. Say I have two DB tables: User ---- Id Name Phone ----- Id UserId Model The Linq code generator produces a bunch of entity classes. I then write my own classes and interfaces which wrap these Linq classes: class DatabaseUser : IUser { public DatabaseUser(User user) { _user = user; } public Guid Id { get { return _user.Id; } } ... etc } so far so good. Now it's easy enough to find a users phones from Phones.Where(p => p.User = user) but surely comsumers of the API shouldn't need to be writing their own Linq queries to get at data, so I should wrap this query in a function or property somewhere. So the question is, in this example, would you add a Phones property to IUser or not? In other words, should my interface specifically be modelling my database objects (in which case Phones doesn't belong in IUser), or are they actually simply providing a set of functions and properties which are conceptually associated with a User (in which case it does)? There seems drawbacks to both views, but I'm wondering if there is a standard approach to the problem. Or just any general words of wisdom you could share. My first thought was to use extension methods but in fact that doesn't work in this case.

    Read the article

  • Can Haskell's monads be thought of as using and returning a hidden state parameter?

    - by AJM
    I don't understand the exact algebra and theory behind Haskell's monads. However, when I think about functional programming in general I get the impression that state would be modelled by taking an initial state and generating a copy of it to represent the next state. This is like when one list is appended to another; neither list gets modified, but a third list is created and returned. Is it therefore valid to think of monadic operations as implicitly taking an initial state object as a parameter and implicitly returning a final state object? These state objects would be hidden so that the programmer doesn't have to worry about them and to control how they gets accessed. So, the programmer would not try to copy the object representing the IO stream as it was ten minutes ago. In other words, if we have this code: main = do putStrLn "Enter your name:" name <- getLine putStrLn ( "Hello " ++ name ) ...is it OK to think of the IO monad and the "do" syntax as representing this style of code? putStrLn :: IOState -> String -> IOState getLine :: IOState -> (IOState, String) main :: IOState -> IOState -- main returns an IOState we can call "state3" main state0 = putStrLn state2 ("Hello " ++ name) where (state2, name) = getLine state1 state1 = putStrLn state0 "Enter your name:"

    Read the article

  • Cocos2d on iPhone: Using Sprites Defined in Separate Class Files.

    - by srikanth rongali
    I'm trying to draw two sprites on the same screen. I have defined the two sprite objects in two separate class files. If I comment out two lines (see "item 1" comment below) then I get a display as [a backgroundimage[background2.jpg] with a sprite[grossini.png] on the left side. If I uncomment the two lines I do not get the background image and sprite of (gameScreen.m). I get only the sprite [grossinis_sister1.png] defined in (enemy.m). But what I need is a [backgroundimage[background2.jpg]], sprite[grossini.png] and sprite [grossinis_sister1.png] in one screen. This is implementation file of my first class: #import "gameScreen.h" #import "enemy.h" @implementation gameScreen -(id)init { if((self = [super init])) { CCSprite *backGroundImage = [CCSprite spriteWithFile:@"background2.jpg"]; backGroundImage.anchorPoint = ccp(0,0); CCParallaxNode *voidNode = [CCParallaxNode node]; [voidNode addChild:backGroundImage z:-1 parallaxRatio:ccp(0.0f,0.0f) positionOffset:CGPointZero]; [self addChild:voidNode]; CGSize windowSize = [[CCDirector sharedDirector] winSize]; CCSprite *player = [CCSprite spriteWithFile:@"grossini.png"]; player.position = ccp(player.contentSize.width/2, windowSize.height/2); [self addChild:player z:0]; //eSprite = [[enemy alloc]init]; //<-- see item 1 //[self addChild:eSprite]; } return self; } This is my implementation file of my second class: #import "enemy.h" #import "gameScreen.h" @implementation enemy -(id)init { if ((self = [super init])) { CGSize windowSize = [[CCDirector sharedDirector] winSize]; CCSprite *enemySprite = [CCSprite spriteWithFile:@"grossinis_sister1.png" ]; enemySprite.position = ccp(windowSize.width/2, windowSize.height/2); [self addChild:enemySprite]; } return self; } @end

    Read the article

  • Valid javascript object property names

    - by hawkettc
    I'm trying to work out what is considered valid for the property name of a javascript object. For example var b = {} b['-^colour'] = "blue"; // Works fine in Firefox, Chrome, Safari b['colour'] = "green"; // Ditto alert(b['-^colour']); // Ditto alert(b.colour); // Ditto for(prop in b) alert(prop); // Ditto //alert(b.-^colour); // Fails (expected) This post details valid javascript variable names, and '-^colour' is clearly not valid (as a variable name). Does the same apply to object property names? Looking at the above I'm trying to work out if b['-^colour'] is invalid, but works in all browsers by quirk, and I shouldn't trust it to work going forward b['-^colour'] is completely valid, but it's just of a form that can only be accessed in this manner - (it's supported so Objects can be used as maps perhaps?) Something else As an aside, a global variable in javascript might be declared at the top level as var abc = 0; but could also be created (as I understand it) with window['abc'] = 0; the following works in all the above browsers window['@£$%'] = "bling!"; alert(window['@£$%']); Is this valid? It seems to contradict the variable naming rules - or am I not declaring a variable there? What's the difference between a variable and an object property name? Cheers, Colin

    Read the article

  • Disable MSBuild output of "Processing /ORDER options..."

    - by Jippers
    The output file from our project build has gone from 6MB to over 75MB in text. Diff'ing the last good build and the first time it blew up, there's a section in the output file like this in the latest: Processing /ORDER options External code objects not listed in the /ORDER file: ?onCallDisconnected@CallStateConnected@CallImpl@space@@UAEXV?$shared_ptr@VCallImpl@space@@@boost@@V?$shared_ptr@VGenericCall@space@@@5@K@Z ; framework.lib(CallStates.obj) ??_DBoolSetting@space@@QAEXXZ ; framework.lib(SettingValueImpl.obj) ...... continues for ~50MB ??$?0U?$pair@$$CBV?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@J@std@@@?$allocator@U_Node@?$_Tree_nod@V?$_Tmap_traits@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@JU?$less@V?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@@2@V?$allocator@U?$pair@$$CBV?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@J@std@@@2@$0A@@std@@@std@@@std@@QAE@ABV?$allocator@U?$pair@$$CBV?$basic_string@_WU?$char_traits@_W@std@@V?$allocator@_W@2@@std@@J@std@@@1@@Z ; CallStatistics.obj Finished processing /ORDER options I'm not sure how this got in there, but anyone know how to turn it off?

    Read the article

  • Omit Properties from WebControl Serialization

    - by Laramie
    I have to serialize several objects inheriting from WebControl for database storage. These include several unecessary (to me) properties that I would prefer to omit from serialization. For example BackColor, BorderColor, etc. Here is an example of an XML serialization of one of my controls inheriting from WebControl. <Control xsi:type="SerializePanel"> <ID>grCont</ID> <Controls /> <BackColor /> <BorderColor /> <BorderWidth /> <CssClass>grActVid bwText</CssClass> <ForeColor /> <Height /> <Width /> ... </Control> I have been trying to create a common base class for my controls that inherits from WebControl and uses the "xxxSpecified" trick to selectively choose not to serialize certain properties. For example to ignore an empty BorderColor property, I'd expect [XmlIgnore] public bool BorderColorSpecified() { return !base.BorderColor.IsEmpty; } to work, but it's never called during serialization. I've also tried it in the class to be serialized as well as the base class. Since the classes themselves might change, I'd prefer not to have to create a custom serializer. Any ideas?

    Read the article

  • Android - Memory leak when dynamically building UI with image resource backgrounds

    - by Rich
    I have an Activity that I swear is leaking memory. The app I'm working on does a lot with images, so I've had to be pretty stingy with memory when working directly with Bitmaps. I added an Activity, and now if you use this new Activity it basically puts me over the edge with mem usage and I end up throwing the "Bitmap exceeds VM budget" exception. If you never launch this Activity, everything is smooth as it was previously. I started reading about memory leaks, and I think that I have a similar situation to what is described in the article in the Android docs. I'm dynamically creating a bunch of image views and adding a BackgroundDrawable from the resources and adding an OnClickListener as well. I imagine I have to do some cleanup when the Activity hits onPause in its life cycle, but I'd like to know specifically what is the correct way. Here is the code that should demonstrate the objects I'm working with... LinearLayout templateContainer; . . . ImageView imgTemplatePreview = (ImageView) item.findViewById(R.id.imgTemplatePreview); . . . imgTemplatePreview.setBackgroundDrawable(getResources().getDrawable(previewId)); imgTemplatePreview.setOnClickListener(imgClick); templateContainer.addView(item);

    Read the article

  • JPA returning null for deleted items from a set

    - by Jon
    This may be related to my question from a few days ago, but I'm not even sure how to explain this part. (It's an entirely different parent-child relationship.) In my interface, I have a set of attributes (Attribute) and valid values (ValidValue) for each one in a one-to-many relationship. In the Spring MVC frontend, I have a page for an administrator to edit these values. Once it's submitted, if any of these fields (as <input> tags) are blank, I remove the ValidValue object like so: Set<ValidValue> existingValues = new HashSet<ValidValue>(attribute.getValidValues()); Set<ValidValue> finalValues = new HashSet<ValidValue>(); for(ValidValue validValue : attribute.getValidValues()) { if(!validValue.getValue().isEmpty()) { finalValues.add(validValue); } } existingValues.removeAll(finalValues); for(ValidValue removedValue : existingValues) { getApplicationDataService().removeValidValue(removedValue); } attribute.setValidValues(finalValues); getApplicationDataService().modifyAttribute(attribute); The problem is that while the database is updated appropriately, the next time I query for the Attribute objects, they're returned with an extra entry in their ValidValue set -- a null, and thus, the next time I iterate through the values to display, it shows an extra blank value in the middle. I've confirmed that this happens at the point of a merge or find, at the point of "Execute query ReadObjectQuery(entity.Attribute). Here's the code I'm using to modify the database (in the ApplicationDataService): public void modifyAttribute(Attribute attribute) { getJpaTemplate().merge(attribute); } public void removeValidValue(ValidValue removedValue) { ValidValue merged = getJpaTemplate().merge(removedValue); getJpaTemplate().remove(merged); } Here are the relevant parts of the entity classes: Entity @Table(name = "attribute") public class Attribute { @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "attribute") private Set<ValidValue> validValues = new HashSet<ValidValue>(0); } @Entity @Table(name = "valid_value") public class ValidValue { @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "attr_id", nullable = false) private Attribute attribute; }

    Read the article

  • Java reflection appropriateness

    - by jsn
    This may be a fairly subjective question, but maybe not. My application contains a bunch of forms that are displayed to the user at different times. Each form is a class of its own. Typically the user clicks a button, which launches a new form. I have a convenience function that builds these buttons, you call it like this: buildButton( "button text", new SelectionAdapter() { @Override public void widgetSelected( SelectionEvent e ) { showForm( new TasksForm( args... ) ); } } ); I do this dozens of times, and it's really cumbersome having to make a SelectionAdapter every time. Really all I need for the button to know is what class to instantiate when it's clicked and what arguments to give the constructor, so I built a function that I call like this instead: buildButton( "button text", TasksForm.class, args... ); Where args is an arbitrary list of objects that you could use to instantiate TasksForm normally. It uses reflection to get a constructor from the class, match the argument list, and build an instance when it needs to. Most of the time I don't have to pass any arguments to the constructor at all. The downside is obviously that if I'm passing a bad set of arguments, it can't detect that at compilation time, so if it fails, a dialog is displayed at runtime. But it won't normally fail, and it'll be easy to debug if it does. I think this is much cleaner because I come from languages where the use of function and class literals is pretty common. But if you're a normal Java programmer, would seeing this freak you out, or would you appreciate not having to scan a zillion SelectionAdapters?

    Read the article

  • check if two subsets of integers are equal using equals method

    - by MAS
    I have this java method in class called IntArray. The class has methods to add integers to a set or remove integers from a set,check size of a set, and check if 2 sets are equal. the 2 sets are created using 2 different objects of type IntArray in main, lets say object A and B. equals method supposed to check if two sets of integers are equal. for example set A = {1,2,3} and B = {1,2,3,4}. The method still return true even though one set is a subset of the other set. What exactly I am doing wrong? Thanks. //part of the code in main IntArray A = new IntArray(); IntArray B = new IntArray(); if(A.equals(B)) System.out.println("A and B are equal"); //equals method in IntArray class public boolean equals(Object b) { if (b instanceof IntArray) { IntArray A = (IntArray) b; for (int i = 0; i < data.length; i++) if (countOccurrences(data[i]) != A.countOccurrences(data[i])) return false; return true; } else return false; }

    Read the article

  • When is a try catch not a try catch?

    - by Dearmash
    I have a fun issue where during application shutdown, try / catch blocks are being seemingly ignored in the stack. I don't have a working test project (yet due to deadline, otherwise I'd totally try to repro this), but consider the following code snippet. public static string RunAndPossiblyThrow(int index, bool doThrow) { try { return Run(index); } catch(ApplicationException e) { if(doThrow) throw; } return ""; } public static string Run(int index) { if(_store.Contains(index)) return _store[index]; throw new ApplicationException("index not found"); } public static string RunAndIgnoreThrow(int index) { try { return Run(index); } catch(ApplicationException e) { } return ""; } During runtime this pattern works famously. We get legacy support for code that relies on exceptions for program control (bad) and we get to move forward and slowly remove exceptions used for program control. However, when shutting down our UI, we see an exception thrown from "Run" even though "doThrow" is false for ALL current uses of "RunAndPossiblyThrow". I've even gone so far as to verify this by modifying code to look like "RunAndIgnoreThrow" and I'll still get a crash post UI shutdown. Mr. Eric Lippert, I read your blog daily, I'd sure love to hear it's some known bug and I'm not going crazy. EDIT This is multi-threaded, and I've verified all objects are not modified while being accessed

    Read the article

  • Rationale in selecting Hash Key type

    - by Amrish
    Guys, I have a data structure which has 25 distinct keys (integer) and a value. I have a list of these objects (say 50000) and I intend to use a hash table to store/retrieve them. I am planning to take one of these approaches. Create a integer hash from these 25 integer keys and store it on a hash table. (Yeah! I have some means to handle collisions) Make a string concatenation on the individual keys and use it as a hash key for the hash table. For example, if the key values are 1,2,4,6,7 then the hash key would be "12467". Assuming that I have a total of 50000 records each with 25 distinct keys and a value, then will my second approach be a overkill when it comes to the cost of string comparisons it needs to do to retrieve and insert a record? Some more information! Each bucket in the hash table is a balanced binary tree. I am using the boost library's hash_combine method to create the hash from the 25 keys.

    Read the article

  • What problem did MS solve by creating PowerShell? [closed]

    - by Fred
    I'm asking because PowerShell confuses me. I've been trying to write some deployment scripts using PowerShell and I've been less than enthused by the result. I have a co-worker who loves PowerShell and defends it at every turn. Said co-worker claims PowerShell was never written to be a strong shell, but instead was written to: a) Allow you to peek and poke at .NET assemblies on the command-line (why is this a reason for PowerShell to exist?) b) To be hosted in .NET applications for automation, similar to DCOP in KDE and how Gnome is using CORBA. c) to be treated as ".NET script" rather than as an actual shell (related to b). I've always felt like Windows was missing a decent way to bang out automation scripts. cmd is too simplistic in many cases, and WSH is too obtuse (although the combination can be used successfully, I'm not a fan). When I first heard about PowerShell I felt like Windows was finally getting a decent shell that would be able to help with automation of many tasks, but recent experiences, and my co-worker, tell me otherwise. To be clear, I don't take issue with the fact that it's built on .NET, or that it passes objects around rather than text (despite my Unix background :]), and I'm not arguing that PowerShell is useless, but from what I can see, it doesn't solve the problem I was hoping it would solve very well. As soon as you step outside of the .NET/Powershell world, things quit being nice and cozy for you. So with all that out of the way, what problem did MS solve by creating PowerShell, or is it some political bastard child as I suspect? I've googled and haven't hit upon anything that sufficiently answered that for me, but the more citations the better.

    Read the article

  • Multiple "ObjectChangeTracker" getting created, can it be avoided?

    - by user555937
    Hi, We are working on a POC where we have following architecture (MVVM), WPF(Client) + WCF + Model(DataAccess)+ ADO.Net Entity Framework 4.0 (with SQL Server 2008 R2 as DB) All are different projects. In the DataAccess layer we have created different Entity Models(edmx) based on the functionality. The tables under perticular flow are grouped and created different entity models. We are using self tracking entities to and fro to communicate with the WPF client through wcf service. For Single model everything works fine. But when we created a Multiple models then few issues started coming. Mutliple models have few duplicate tables/entities. Two probels are, 1) When we try to access entities from different models mutiple objects "ObjectChangeTracker" are getting created. E.g. CompanyModel(edmx) - Company(Entity) - ObjectChangeTracker, ObjectState ProductModel(edmx) - Customer(Entity) - ObjectChangeTracker1, ObjectState1 OrderModel(edmx) - Oder(Entity) - ObjectChangeTracker2, ObjectState2 Is there any way to avoid this? 2) There are few tables which shared across the Models, E.g. Company(Entity) is used in All above mdoels. During compile time it does not thow any error. But run time It gives error saying "Schema specified is not valid. Errors: The mapping of CLR type to EDM type is ambiguous because multiple CLR types match the EDM type "Company"".. To resolve this, we renamed the entities with some prefix to make them Unique. Is there any other way we can resolve this without changing the name of the entity in the same assembly? Thanks in advance and appreciate if anyone has approach for these issues. Thanks, Kiran

    Read the article

  • After calling a COM-dll component, C# exceptions are not caught by the debugger

    - by shlomil
    I'm using a COM dll provided to me by 3rd-party software company (I don't have the source code). I do know for sure they used Java to implement it because their objects contain property names like 'JvmVersion'. After I instantiated an object introduced by the provided COM dll, all exceptions in my C# program cannot be caught by the VS debugger and every time an exception occurs I get the default Windows Debugger Selection dialog (And that's while executing my program in debug mode under a full VisualStudio debugging environment). To illustrate: throw new Exception("exception 1"); m_moo = new moo(); // Component taken from the COM-dll throw new Exception("exception 2"); Exception 1 will be caught by VS and show the "yellow exception window". Exception 2 will open a dialog titled "Visual Studio Just-In-Time Debugger" containing the text "An unhandled win32 exception occurred in myfile.vshost.exe[1348]." followed by a list of the existing VS instances on my system to select from. I guess the instantiation of "moo" object overrides C#'s exception handler or something like that. Am I correct and is there a way to preserve C#'s exception handler?

    Read the article

  • Flex Tree with infinite parents and children

    - by Tempname
    I am working on a tree component and I am having a bit of the issue with populating the data-provider for this tree. The data that I get back from my database is a simple array of value objects. Each value object has 2 properties. ObjectID and ParentID. For parents the ParentID is null and for children the ParentID is the ObjectID of the parent. Any help with this is greatly appreciated. Essentially the tree should look something like this: Parent1 Child1 Child1 Child2 Child1 Child2 Parent2 Child1 Child2 Child3 Child1 This is the current code that I am testing with: public function setDataProvider(data:Array):void { var tree:Array = new Array(); for(var i:Number = 0; i < data.length; i++) { // do the top level array if(!data[i].parentID) { tree.push(data[i], getChildren(data[i].objectID, data)); } } function getChildren(objectID:Number, data:Array):Array { var childArr:Array = new Array(); for(var k:Number = 0; k < data.length; k++) { if(data[k].parentID == objectID) { childArr.push(data[k]); //getChildren(data[k].objectID, data); } } return childArr; } trace(ObjectUtil.toString(tree)); } Here is a cross section of my data: ObjectID ParentID 1 NULL 10 NULL 8 NULL 6 NULL 4 6 3 6 9 6 2 6 11 7 7 8 5 8

    Read the article

  • FileConnection Blackberry memory usage

    - by Dean
    Hello, I'm writing a blackberry application that reads ints and strings out of a database. This is my first time dealing with reading/writing on the blackberry, so forgive me if this is a dumb question. The database file I'm reading is only about 4kB I open the file with the following code fconn = (FileConnection) Connector.open("file_path_here", Connector.READ); if(fconn.exists()==false){fconn.close();return;} is = fconn.openDataInputStream(); while(!eof){ //etc... } is.close(); fconn.close(); The problem is, this code appears to be eating a LOT of memory. Using breakpoints and the "Memory Statistics" view, I determined the following: calling "Connector.open" creates 71 objects and changes "RAM Bytes in use" by 5376 calling "fconn.openDataInputStream();" increases RAM usage by a whopping 75920 Is this normal? Or am I doing something wrong? And how can I fix this? 75MB of RAM is a LOT of memory to waste on a handheld device, especially when the file I'm reading is only 4kB and I haven't even begun reading any data! How is this even possible?

    Read the article

  • Concrete examples of state sharing between multiple viewmodels (WPF MVVM)

    - by JohnMetta
    I have a WPF/Entity Framework (4.0) project with many objects. I'd like to build the application so that that I can have object selection state shared across viewmodels. For Example: We have Cars, Drivers, Passengers, and Cargo classes. We also have UserControls for CarList, DriverList, etc. and editor windows for CarEditor, DriverEditor, etc. Furthermore, we have viewmodels for all of these (CarListViewModel, DriverListViewModel, CargoEditorViewModel, etc). This all composes a dockable interface where the user can have multiple object lists, editors, and viewers open. What I want is a concrete code example of how to wireup multiple viewmodels so that selecting a car in the CarList will cause that car to go live in the CarEditorView, but also be selected in any other view for which the context is valid (such as a DriverByCarView- or just DriverList if there is a filter predicate). There are a number of suggestions and discussions based on this question. The two methods that seem to dominate are: 3018307: Discusses state sharing by mentioning a messaging subsystem 1159035: Discusses state sharing by using an enclosing viewmodel Is one of these approaches better than the other? Does anyone have a concrete example of either/both of these methods in the form of a write-up or small code project? I'm still learning WPF, so pointers to entry points for reading API fundamentals are appreciated, but looking at code examples is where I usually go. Thanks In case anyone is interested, here are some other similar discussions: 3816961: Discusses returning multiple viewmodels depending on object type (i.e. a collection of arbitrary types adhering to a specific interface) 1928130: Discusses whether it is a good idea to aggregate viewmodels as properties of other viewmodels (e.g. a MainWindow viewmodel composed of panel viewmodels) 1120061: Essentially discusses whether to have use a viewmodel-per-model strategy or a viewmodel-per-view-element strategy. 4244222: Discusses whether or not to nest the viewmodels when using a nested object hierarchy. 4429708: Discusses sharing collections between viewmodels directly, but doesn't go into detail. List item: Discusses managing multiple selections within a single viewmodel.

    Read the article

< Previous Page | 485 486 487 488 489 490 491 492 493 494 495 496  | Next Page >