Window.Close() from XAML

It’s been a long time since I last posted. Since then I have been working on my first WPF contract. I have definately drank the cool aid, I love WPF (when MVVM is being used anyway).

One thing I haven’t been able to find any info on is how to close a window or dialog from XAML. I tried and tried and then gave up. Until now!

Having discovered the power of Attached Behaviours, I decided to write one that would close a window. All you need do then is create a data trigger that watches a CloseSignal on the ViewModel and sets the Close property to true.

public static class WindowCloseBehaviour
{
public static void SetClose(DependencyObject target, bool value)
{
target.SetValue(CloseProperty, value);
}
public static readonly DependencyProperty CloseProperty =
DependencyProperty.RegisterAttached(
"Close",
typeof(bool),
typeof(WindowCloseBehaviour),
new UIPropertyMetadata(false, OnClose));
private static void OnClose(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
if (e.NewValue is bool && ((bool)e.NewValue))
{
Window window = GetWindow(sender);
if (window != null)
window.Close();
}
}
private static Window GetWindow(DependencyObject sender)
{
Window window = null;
if (sender is Window)
window = (Window)sender;
if (window == null)
window = Window.GetWindow(sender);
return window;
}
}

and then in your XAML

<Style.Triggers>
   <DataTrigger Binding="{Binding CloseSignal}" Value="true">
        <Setter Property="Behaviours:WindowCloseBehaviour.Close" Value="true" />
   </DataTrigger>
</Style>