How to bind Close command to a button

All it takes is a bit of XAML...

<Window x:Class="WCSamples.Window1"        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">    <Window.CommandBindings>        <CommandBinding Command="ApplicationCommands.Close"                        Executed="CloseCommandHandler"/>    </Window.CommandBindings>    <StackPanel Name="MainStackPanel">        <Button Command="ApplicationCommands.Close"                 Content="Close Window" />    </StackPanel></Window>

And a bit of C#...

private void CloseCommandHandler(object sender, ExecutedRoutedEventArgs e){    this.Close();}

(adapted from this MSDN article)

Actually, it is possible without C# code. The key is to use interactions:

<Button Content="Close">  <i:Interaction.Triggers>    <i:EventTrigger EventName="Click">      <ei:CallMethodAction TargetObject="{Binding ElementName=window}" MethodName="Close"/>    </i:EventTrigger>  </i:Interaction.Triggers></Button>

In order for this to work, just set the x:Name of your window to "window", and add these two namespaces:

xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity" xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"

This requires that you add the Expression Blend SDK DLL to your project, specifically Microsoft.Expression.Interactions.

In case you don't have Blend, the SDK can be downloaded here.

I think that in real world scenarios a simple click handler is probably better than over-complicated command-based systems but you can do something like that:

using RelayCommand from this article http://msdn.microsoft.com/en-us/magazine/dd419663.aspx

public class MyCommands{    public static readonly ICommand CloseCommand =        new RelayCommand( o => ((Window)o).Close() );}

<Button Content="Close Window"        Command="{X:Static local:MyCommands.CloseCommand}"        CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor,                            AncestorType={x:Type Window}}}"/>