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  • Unable to access static var from Document Class in AS3

    - by omidomid
    I have a Document class called "CityModule", and an asset with class "City". Below is the coe for each. For some reason, I am unable to access the static variables of the City class from CityModule: CityModule.as: package { public class CityModule extends MovieClip { public function CityModule() { var buildings:Array = City.getBuildings(); } } } } City.as: package { import flash.display.MovieClip; public class City extends MovieClip { private static var _buildings:Array = [ {className:'City.Generic1', type:'generic'}, {className:'City.Generic2', type:'generic'}, {className:'City.Generic3', type:'generic'} ]; public function City(){ //empty } public static function getBuildings():Array{ return _buildings; } } } Doing this gives me a "Call to a possibly undefined method getBuildings" error. If I instantiate an instance of City, I can see any public/ getters/ setters perfectly fine. But static isn't working...

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  • Binding in ContentControl Crash

    - by ImJames
    Can anyone tell me why this crashes my app? There seems to be some endless recursion by I can't figure out why. I get this exception Logical tree depth exceeded while traversing the tree. This could indicate a cycle in the tree <ContentControl Content="{Binding}"> <ContentControl.ContentTemplate> <DataTemplate> <Button Content="{Binding MyString}"/> </DataTemplate> </ContentControl.ContentTemplate> </ContentControl> And this is all I have as Source public MainWindow() { InitializeComponent(); MyString = "Test"; this.DataContext = this; } public string MyString { get; set; }

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  • CodeIgniter static class question

    - by Josh K
    If I would like to have several static methods in my models so I can say User::get_registered_users() and have it do something like public static function get_registered_users() { $sql = "SELECT * FROM `users` WHERE `is_registered` = 0"; $this->db->query($sql); // etc... } Is it possible to access the $this->db object or create a new one for a static method?

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  • How to free static member variable in C++?

    - by user299831
    Can anybody explain how to free memory of a static member Variable? In my understanding it can only be freed if all the instances of the class are destroyed. I am a little bit helpless at this point... Some Code to explain it: class ball { private: static SDL_Surface *ball_image; }; //FIXME: how to free static Variable? SDL_Surface* ball::ball_image = SDL_LoadBMP("ball.bmp");

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  • C++ static virtual members?

    - by cvb
    Is it possible in C++ to have a member function that is both static and virtual? Apperantly, there isn't a straight-forward way to do it (static virtual member(); is a complie error), but at least a way to acheive the same effect? I.E: struct Object { struct TypeInformation; static virtual const TypeInformation &GetTypeInformation() const; }; struct SomeObject : public Object { static virtual const TypeInformation &GetTypeInformation() const; }; It makes sence to use GetTypeInformation() both on an instance (object->GetTypeInformation()) and on a class (SomeObject::GetTypeInformation()), which can be useful for comparsions and vital for templates. The only ways I can think of involves writing two functions / a function and a constant, per class, or use macros. Any other solutions?

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  • MVC4 not binding a list of basic types

    - by admanb
    I cannot, for the life of me, get this data to bind. Here's my JavaScript: var params = { 'InvItemIDs': ["188475", "188490"]}; $.post("api/Orders/OrderFromInventory?" + $.param(params)) and the Controller action: public HttpResponseMessage OrderFromInventory(IList<int> InvItemIDs) { return new HttpResponseMessage(); } I've built the query string so that it's sending: ?InvItemIDs=188475&InvItemIDs=188490 as well as ?InvItemIDs[]=188475&InvItemIDs[]=188490 and even ?InvItemIDs[0]=188475&InvItemIDs[1]=188490 and none of them are binding. InvItemIDs is always null. What am I doing wrong? EDIT: So it turns out all this is a bug (or something) in the new Web API controller code in MVC4. As soon as I moved the exact same code over to a standard controller it started working. I'm still interested if anyone has any insight as to why the Web API would break this binding.

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  • Silverlight 4 Binding to ConverterParameter

    - by FrEEzE2046
    Hello everybody, I have a ValueConverter which needs to be called with a dynamic parameter, depending on a property. I can't see a way to do this ... Width="{Binding ActualWidthValue, Source={StaticResource VisibleSize}, Converter={StaticResource Fraction}}" The "Fraction" converter get's (or should get) a parameter of type System.Size, which contains a numerator and denumerator. This value (should) depend on a ItemCollection.Count. Resetting the ItemCollection should reinvoke the Converter with the new values. My first idea was to manually change the ConverterParameter in CodeBehind on the PropertyChanged event of my ItemCollection DependencyProperty. But, as I know now, Silverlight has no GetBinding() method. I heard about GetBindingExpression and tried to do. But MyGrid.GetBindingExpression(Grid.ActualHeightProperty) is always returning null, although the Binding is already established. So, what can I do to reach my target?

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  • Why does this static field always get initialized over-eagerly?

    - by TheSilverBullet
    I am looking at this excellent article from Jon Skeet. While executing the demo code, Jon Skeet says that we can expect three different kinds of behaviours. To quote that article: The runtime could decide to run the type initializer on loading the assembly to start with... Or perhaps it will run it when the static method is first run... Or even wait until the field is first accessed... When I try this out (on framework 4), I always get the first result. That is, the static method is initialized before the assembly is loaded. I have tried running this multiple times and get the same result. (I tried both the debug and release versions) Why is this so? Am I missing something?

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  • Make methods that do not depend on instance fields, static?

    - by m3th0dman
    Recently I started programming in Groovy for a integration testing framework, for a Java project. I use Intellij IDEA with Groovy plug-in and I am surprised to see as a warning for all the methods that are non-static and do not depend on any instance fields. In Java, however, this is not an issue (at least from IDE's point of view). Should all methods that do not depend onto any instance fields be transformed into static functions? If true, is this specific to Groovy or it is available for OOP in general? And why?

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  • C#4: Why does this static field always get initialized over-eagerly?

    - by TheSilverBullet
    I am looking at this excellent article from Jon Skeet at this location: http://csharpindepth.com/Articles/General/Beforefieldinit.aspx While executing the demo code, Jon Skeet says that we can expect three different kinds of behaviours. To quote that article: The runtime could decide to run the type initializer on loading the assembly to start with... Or perhaps it will run it when the static method is first run... Or even wait until the field is first accessed... When I try this out (on framework 4), I always get the first result. That is, the static method is initialized before the assembly is loaded. I have tried running this multiple times and get the same result. (I tried both the debug and release versions) Why is this so? Am I missing something?

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  • What is the difference between all-static-methods and applying a singleton pattern?

    - by shahensha
    I am making a database to store information about the users of my website (I am using stuts2 and hence Java EE technology). For the database I'll be making a DBManager. Should I apply singleton pattern here or rather make all it's methods static? I will be using this DBManager for basic things like adding, deleting and updating User profiles. Along with it, I'll use for all other querying purposes, for instance to find out whether a username already exists and to get all users for administrative purposes and stuff like that. My questions What is the benefit of singleton pattern? Which thing is most apt here? All static methods or a singleton pattern? Please compare both of them. regards shahensha P.S. The database is bigger than this. Here I am talking only about the tables which I'll be using for storing User Information.

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  • Requriing static class setter to be called before Constructor, bad design?

    - by roverred
    I have a class, say Foo, and every instance of Foo will need and contain the same List object, myList. Since every class instance will share the same List Object, I thought it would be good to make myList static and use a static function to set myList before the constructor is called. I was wondering if this was bad, because this requires the setter to be called before the constructor. If the person doesn't, the program will crash. Alternative way would be passing myList every time. Thanks.

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  • What is the difference between all-static-methods and applying a singleton pattern?

    - by shahensha
    I am making a database to store information about the users of my website (I am using stuts2 and hence Java EE technology). For the database I'll be making a DBManager. Should I apply singleton pattern here or rather make all it's methods static? I will be using this DBManager for basic things like adding, deleting and updating User profiles. Along with it, I'll use for all other querying purposes, for instance to find out whether a username already exists and to get all users for administrative purposes and stuff like that. My questions What is the benefit of singleton pattern? Which thing is most apt here? All static methods or a singleton pattern? Please compare both of them. P.S. The database is bigger than this. Here I am talking only about the tables which I'll be using for storing User Information.

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  • Apache - Serving static files from different subdomain + machine

    - by rubayeet
    Here's the scenario A site is running on this domain - www.someserver.com I'm going to host subdomain.someserver.com on my machine. Let's say all the image files are under the directory 'img'. I don't want to copy all their images to my machine. So what should be the Apache directive(s) that'll map the request for an image, like http://subdomain.someserver.com/img/image.png to http://www.someserver.com/img/image.png

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  • Static Routes and the Routing Table

    - by TheD
    This is very much a learning question if someone would be happy to explain a couple of concepts. My question is - the default routing table that exists in, in my case, a default Windows 7 install, what do each of the routes in the table do? Here is a screenshot: The 10.128.4.0 is just a route I've added while messing. I understand from a question I posted on Superuser the first route is just a default route that will route all traffic for any IP to my default gateway on my Interface in use. But what about the others? And how would the routing table handle a machine with multiple NIC's, perhaps connected to two different networks, or maybe even two NIC's on the same network so a VM can have a physical Network card instead of each VM sharing the hosts. Thanks!

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  • Static Route Qestion

    - by mrlayance
    I have a Wan simulator between 2 networks. I can ping both networks from the wan simulator, but I can not ping from one network to the other. testr01 Fa0/0 10.0.0.1/24 FA0/1 192.168.0.1/30 | | Wan Sim 2 nics Eth0 192.168.0.2/30 | Eth1 192.168.1.2/30 | | testr02 Fa0/1 192.168.1.1/30 Fa0/0 10.1.0.2/24 I can not figure out what type of routes I need. On the route? On the Server? I guess all 10. traffic to the Fa0/0 ports? Thanks

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  • Generate static gallery

    - by theomega
    Hy, I need a (linux/shell) script which does the following: It takes a folder full of jpg-files, generates thumbnails and previews (maybe using imagemagik's convert) and creates a html-page which includes all the thumbnails, opens a preview using something like LightBox and links to the original size. Does somebody know a script which does this? I could write one on my own, but it would save me some time.

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  • Unable to get HTTPS MEX endpoint to work

    - by Rahul
    I have been trying to configure WCF to work with Azure ACS. This WCF configuration has 2 bugs: It does not publish MEX end point. It does not invoke custom behaviour extension. (It just stopped doing that after I made some changes which I can't remember) What could be possibly wrong here? <configuration> <configSections> <section name="microsoft.identityModel" type="Microsoft.IdentityModel.Configuration.MicrosoftIdentityModelSection, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> </configSections> <location path="FederationMetadata"> <system.web> <authorization> <allow users="*" /> </authorization> </system.web> </location> <system.web> <compilation debug="true" targetFramework="4.0"> <assemblies> <add assembly="Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" /> </assemblies> </compilation> </system.web> <system.serviceModel> <services> <service name="production" behaviorConfiguration="AccessServiceBehavior"> <endpoint contract="IMetadataExchange" binding="mexHttpsBinding" address="mex" /> <endpoint address="" binding="customBinding" contract="Samples.RoleBasedAccessControl.Service.IService1" bindingConfiguration="serviceBinding" /> </service> </services> <behaviors> <serviceBehaviors> <behavior name="AccessServiceBehavior"> <federatedServiceHostConfiguration /> <sessionExtension/> <useRequestHeadersForMetadataAddress> <defaultPorts> <add scheme="http" port="8000" /> <add scheme="https" port="8443" /> </defaultPorts> </useRequestHeadersForMetadataAddress> <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment --> <serviceMetadata httpsGetEnabled="true" /> <!-- To receive exception details in faults for debugging purposes, set the value below to true. Set to false before deployment to avoid disclosing exception information --> <serviceDebug includeExceptionDetailInFaults="true" /> <serviceCredentials> <!--Certificate added by FedUtil. Subject='CN=DefaultApplicationCertificate', Issuer='CN=DefaultApplicationCertificate'.--> <serviceCertificate findValue="XXXXXXXXXXXXXXX" storeLocation="LocalMachine" storeName="My" x509FindType="FindByThumbprint" /> </serviceCredentials> </behavior> </serviceBehaviors> </behaviors> <serviceHostingEnvironment multipleSiteBindingsEnabled="true" /> <extensions> <behaviorExtensions> <add name="sessionExtension" type="Samples.RoleBasedAccessControl.Service.RsaSessionServiceBehaviorExtension, Samples.RoleBasedAccessControl.Service, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" /> <add name="federatedServiceHostConfiguration" type="Microsoft.IdentityModel.Configuration.ConfigureServiceHostBehaviorExtensionElement, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> </behaviorExtensions> </extensions> <protocolMapping> <add scheme="http" binding="customBinding" bindingConfiguration="serviceBinding" /> <add scheme="https" binding="customBinding" bindingConfiguration="serviceBinding"/> </protocolMapping> <bindings> <customBinding> <binding name="serviceBinding"> <security authenticationMode="SecureConversation" messageSecurityVersion="WSSecurity11WSTrust13WSSecureConversation13WSSecurityPolicy12BasicSecurityProfile10" requireSecurityContextCancellation="false"> <secureConversationBootstrap authenticationMode="IssuedTokenOverTransport" messageSecurityVersion="WSSecurity11WSTrust13WSSecureConversation13WSSecurityPolicy12BasicSecurityProfile10"> <issuedTokenParameters> <additionalRequestParameters> <AppliesTo xmlns="http://schemas.xmlsoap.org/ws/2004/09/policy"> <EndpointReference xmlns="http://www.w3.org/2005/08/addressing"> <Address>https://127.0.0.1:81/</Address> </EndpointReference> </AppliesTo> </additionalRequestParameters> <claimTypeRequirements> <add claimType="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name" isOptional="true" /> <add claimType="http://schemas.microsoft.com/ws/2008/06/identity/claims/role" isOptional="true" /> <add claimType="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/nameidentifier" isOptional="true" /> <add claimType="http://schemas.microsoft.com/accesscontrolservice/2010/07/claims/identityprovider" isOptional="true" /> </claimTypeRequirements> <issuerMetadata address="https://XXXXYYYY.accesscontrol.windows.net/v2/wstrust/mex" /> </issuedTokenParameters> </secureConversationBootstrap> </security> <httpsTransport /> </binding> </customBinding> </bindings> </system.serviceModel> <system.webServer> <modules runAllManagedModulesForAllRequests="true" /> </system.webServer> <microsoft.identityModel> <service> <audienceUris> <add value="http://127.0.0.1:81/" /> </audienceUris> <issuerNameRegistry type="Microsoft.IdentityModel.Tokens.ConfigurationBasedIssuerNameRegistry, Microsoft.IdentityModel, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"> <trustedIssuers> <add thumbprint="THUMBPRINT HERE" name="https://XXXYYYY.accesscontrol.windows.net/" /> </trustedIssuers> </issuerNameRegistry> <certificateValidation certificateValidationMode="None" /> </service> </microsoft.identityModel> <appSettings> <add key="FederationMetadataLocation" value="https://XXXYYYY.accesscontrol.windows.net/FederationMetadata/2007-06/FederationMetadata.xml " /> </appSettings> </configuration> Edit: Further implementation details I have the following Behaviour Extension Element (which is not getting invoked currently) public class RsaSessionServiceBehaviorExtension : BehaviorExtensionElement { public override Type BehaviorType { get { return typeof(RsaSessionServiceBehavior); } } protected override object CreateBehavior() { return new RsaSessionServiceBehavior(); } } The namespaces and assemblies are correct in the config. There is more code involved for checking token validation, but in my opinion at least MEX should get published and CreateBehavior() should get invoked in order for me to proceed further.

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  • Dependency Property Set Priority: CodeBehind vs. XAML

    - by LukePet
    When I initialize a control property from code, the binding to the same property defined on XAML don't work. Why? For Example, I set control properties on startup with this statements: myControl.SetValue(UIElement.VisibilityProperty, DefaultProp.Visibility); myControl.SetValue(UIElement.IsEnabledProperty, DefaultProp.IsEnabled); and on xaml I bind the property of myControl in this way: IsEnabled="{Binding Path=IsKeyControlEnabled}" now, when the property "IsKeyControlEnabled" changes to false, myControl remains enabled (because it's initialize with true value). How can I do?

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  • MVVM: Binding radio buttons to a view model?

    - by David Veeneman
    I have been trying to bind a group of radio buttons to a view model using the IsChecked button. After reviewing other posts, it appears that the IsChecked property simply doesn't work. I have put together a short demo that reproduces the problem, which I have included below. Here is my question: Is there a straightforward and reliable way to bind radio buttons using MVVM? Thanks. Additional information: The IsChecked property doesn't work for two reasons: When a button is selected, the IsChecked properties of other buttons in the group don't get set to false. When a button is selected, its own IsChecked property does not get set after the first time the button is selected. I am guessing that the binding is getting trashed by WPF on the first click. Demo project: Here is the code and markup for a simple demo that reproduces the problem. Create a WPF project and replace the markup in Window1.xaml with the following: <Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300" Loaded="Window_Loaded"> <StackPanel> <RadioButton Content="Button A" IsChecked="{Binding Path=ButtonAIsChecked, Mode=TwoWay}" /> <RadioButton Content="Button B" IsChecked="{Binding Path=ButtonBIsChecked, Mode=TwoWay}" /> </StackPanel> </Window> Replace the code in Window1.xaml.cs with the following code (a hack), which sets the view model: using System.Windows; namespace WpfApplication1 { /// <summary> /// Interaction logic for Window1.xaml /// </summary> public partial class Window1 : Window { public Window1() { InitializeComponent(); } private void Window_Loaded(object sender, RoutedEventArgs e) { this.DataContext = new Window1ViewModel(); } } } Now add the following code to the project as Window1ViewModel.cs: using System.Windows; namespace WpfApplication1 { public class Window1ViewModel { private bool p_ButtonAIsChecked; /// <summary> /// Summary /// </summary> public bool ButtonAIsChecked { get { return p_ButtonAIsChecked; } set { p_ButtonAIsChecked = value; MessageBox.Show(string.Format("Button A is checked: {0}", value)); } } private bool p_ButtonBIsChecked; /// <summary> /// Summary /// </summary> public bool ButtonBIsChecked { get { return p_ButtonBIsChecked; } set { p_ButtonBIsChecked = value; MessageBox.Show(string.Format("Button B is checked: {0}", value)); } } } } To reproduce the problem, run the app and click Button A. A message box will appear, saying that Button A's IsChecked property has been set to true. Now select Button B. Another message box will appear, saying that Button B's IsChecked property has been set to true, but there is no message box indicating that Button A's IsChecked property has been set to false--the property hasn't been changed. Now click Button A again. The button will be selected in the window, but no message box will appear--the IsChecked property has not been changed. Finally, click on Button B again--same result. The IsChecked property is not updated at all for either button after the button is first clicked.

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  • Silverlight: Binding a custom control to an arbitrary object

    - by Ryan Bates
    I am planning on writing a hierarchical organizational control, similar to an org chart. Several org chart implementations are out there, but not quite fit what I have in mind. Binding fields in a DataTemplate to a custom object does not seem to work. I started with a generic, custom control, i.e. public class NodeBodyBlock : ContentControl { public NodeBodyBlock() { this.DefaultStyleKey = typeof(NodeBodyBlock); } } It has a simple style in generic.xaml: <Style TargetType="org:NodeBodyBlock"> <Setter Property="Width" Value="200" /> <Setter Property="Height" Value="100" /> <Setter Property="Background" Value="Lavender" /> <Setter Property="FontSize" Value="11" /> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="org:NodeBodyBlock"> <Border Width="{TemplateBinding Width}" Height="{TemplateBinding Height}" Background="{TemplateBinding Background}" CornerRadius="4" BorderBrush="Black" BorderThickness="1" > <Grid> <VisualStateManager/> ... clipped for brevity </VisualStateManager.VisualStateGroups> <ContentPresenter Content="{TemplateBinding Content}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" /> </Grid> </Border> </ControlTemplate> </Setter.Value> </Setter> </Style> My plan now is to be able to use this common definition as a base definition of sorts, with customized version of it used to display different types of content. A simple example would be to use this on a user control with the following style: <Style TargetType="org:NodeBodyBlock" x:Key="TOCNode2"> <Setter Property="ContentTemplate"> <Setter.Value> <DataTemplate> <StackPanel> <TextBlock Text="{Binding Path=NodeTitle}"/> </StackPanel> </DataTemplate> </Setter.Value> </Setter> </Style> and an instance defined as <org:NodeBodyBlock Style="{StaticResource TOCNode2}" x:Name="stTest" DataContext="{StaticResource DummyData}" /> The DummyData is defined as <toc:Node NodeNumber="mynum" NodeStatus="A" NodeTitle="INLine Node Title!" x:Key="DummyData"/> With a simple C# class behind it, where each of the fields is a public property. When running the app, the Dummy Data values simply do not show up in the GUI. A trivial test such as <TextBlock Text="{Binding NodeTitle}" DataContext="{StaticResource DummyData}"/> works just fine. Any ideas around where I am missing the plot?

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  • WPF: Binding to ListBoxItem.IsSelected doesn't work for off-screen items

    - by Qwertie
    In my program I have a set of view-model objects to represent items in a ListBox (multi-select is allowed). The viewmodel has an IsSelected property that I would like to bind to the ListBox so that selection state is managed in the viewmodel rather than in the listbox itself. However, apparently the ListBox doesn't maintain bindings for most of the off-screen items, so in general the IsSelected property is not synchronized correctly. Here is some code that demonstrates the problem. First XAML: <StackPanel> <StackPanel Orientation="Horizontal"> <TextBlock>Number of selected items: </TextBlock> <TextBlock Text="{Binding NumItemsSelected}"/> </StackPanel> <ListBox ItemsSource="{Binding Items}" Height="200" SelectionMode="Extended"> <ListBox.ItemContainerStyle> <Style TargetType="{x:Type ListBoxItem}"> <Setter Property="IsSelected" Value="{Binding IsSelected}"/> </Style> </ListBox.ItemContainerStyle> </ListBox> <Button Name="TestSelectAll" Click="TestSelectAll_Click">Select all</Button> </StackPanel> C# Select All handler: private void TestSelectAll_Click(object sender, RoutedEventArgs e) { foreach (var item in _dataContext.Items) item.IsSelected = true; } C# viewmodel: public class TestItem : NPCHelper { TestDataContext _c; string _text; public TestItem(TestDataContext c, string text) { _c = c; _text = text; } public override string ToString() { return _text; } bool _isSelected; public bool IsSelected { get { return _isSelected; } set { _isSelected = value; FirePropertyChanged("IsSelected"); _c.FirePropertyChanged("NumItemsSelected"); } } } public class TestDataContext : NPCHelper { public TestDataContext() { for (int i = 0; i < 200; i++) _items.Add(new TestItem(this, i.ToString())); } ObservableCollection<TestItem> _items = new ObservableCollection<TestItem>(); public ObservableCollection<TestItem> Items { get { return _items; } } public int NumItemsSelected { get { return _items.Where(it => it.IsSelected).Count(); } } } public class NPCHelper : INotifyPropertyChanged { public event PropertyChangedEventHandler PropertyChanged; public void FirePropertyChanged(string prop) { if (PropertyChanged != null) PropertyChanged(this, new PropertyChangedEventArgs(prop)); } } Two separate problems can be observed. If you click the first item and then press Shift+End, all 200 items should be selected; however, the heading reports that only 21 items are selected. If you click "Select all" then all items are indeed selected. If you then click an item in the ListBox you would expect the other 199 items to be deselected, but this does not happen. Instead, only the items that are on the screen (and a few others) are deselected. All 199 items will not be deselected unless you first scroll through the list from beginning to end (and even then, oddly enough, it doesn't work if you perform scrolling with the little scroll box). My questions are: Can someone explain precisely why this occurs? Can I avoid or work around the problem?

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  • Why are static classes considered “classes” and “reference types”?

    - by Timwi
    I’ve been pondering about the C# and CIL type system today and I’ve started to wonder why static classes are considered classes. There are many ways in which they are not really classes: A “normal” class can contain non-static members, a static class can’t. In this respect, a class is more similar to a struct than it is to a static class, and yet structs have a separate name. You can have a reference to an instance of a “normal” class, but not a static class (despite it being considered a “reference type”). In this respect, a class is more similar to an interface than it is to a static class, and yet interfaces have a separate name. The name of a static class can never be used in any place where a type name would normally fit: you can’t declare a variable of this type, you can’t use it as a base type, and you can’t use it as a generic type parameter. In this respect, static classes are somewhat more like namespaces. A “normal” class can implement interfaces. Once again, that makes classes more similar to structs than to static classes. A “normal” class can inherit from another class. It is also bizarre that static classes are considered to derive from System.Object. Although this allows them to “inherit” the static methods Equals and ReferenceEquals, the purpose of that inheritance is questionable as you would call those methods on object anyway. C# even allows you to specify that useless inheritance explicitly on static classes, but not on interfaces or structs, where the implicit derivation from object and System.ValueType, respectively, actually has a purpose. Regarding the subset-of-features argument: Static classes have a subset of the features of classes, but they also have a subset of the features of structs. All of the things that make a class distinct from the other kinds of type, do not seem to apply to static classes. Regarding the typeof argument: Making a static class into a new and different kind of type does not preclude it from being used in typeof. Given the sheer oddity of static classes, and the scarcity of similarities between them and “normal” classes, shouldn’t they have been made into a separate kind of type instead of a special kind of class?

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