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RoutedEventArgs Class

Contains state information and event data associated with a routed event.

Namespace:  System.Windows
Assembly:  PresentationCore (in PresentationCore.dll)
public class RoutedEventArgs : EventArgs
This managed class is not typically used in XAML.

Different RoutedEventArgs can be used with a single RoutedEvent. This class is responsible for packaging the event data for a RoutedEvent, providing extra event state information, and is used by the event system for invoking the handler associated with the routed event.

For your custom event to support event routing, you need to register a RoutedEvent using the RegisterRoutedEvent method. This example demonstrates the basics of creating a custom routed event.

As shown in the following example, you first register a RoutedEvent using the RegisterRoutedEvent method. By convention, the RoutedEvent static field name should end with the suffix Event. In this example, the name of the event is Tap and the routing strategy of the event is Bubble. After the registration call, you can provide add-and-remove common language runtime (CLR) event accessors for the event.

Note that even though the event is raised through the OnTap virtual method in this particular example, how you raise your event or how your event responds to changes depends on your needs.

Note also that this example basically implements an entire subclass of Button; that subclass is built as a separate assembly and then instantiated as a custom class on a separate Extensible Application Markup Language (XAML) page. This is to illustrate the concept that subclassed controls can be inserted into trees composed of other controls, and that in this situation, custom events on these controls have the very same event routing capabilities as any native Windows Presentation Foundation (WPF) element does.

public class MyButtonSimple: Button
{
    // Create a custom routed event by first registering a RoutedEventID 
    // This event uses the bubbling routing strategy 
    public static readonly RoutedEvent TapEvent = EventManager.RegisterRoutedEvent(
        "Tap", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(MyButtonSimple));

    // Provide CLR accessors for the event 
    public event RoutedEventHandler Tap
    {
            add { AddHandler(TapEvent, value); } 
            remove { RemoveHandler(TapEvent, value); }
    }

    // This method raises the Tap event 
    void RaiseTapEvent()
    {
            RoutedEventArgs newEventArgs = new RoutedEventArgs(MyButtonSimple.TapEvent);
            RaiseEvent(newEventArgs);
    }
    // For demonstration purposes we raise the event when the MyButtonSimple is clicked 
    protected override void OnClick()
    {
        RaiseTapEvent();
    }

}
<Window  
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:custom="clr-namespace:SDKSample;assembly=SDKSampleLibrary"
    x:Class="SDKSample.RoutedEventCustomApp"

    >
    <Window.Resources>
      <Style TargetType="{x:Type custom:MyButtonSimple}">
        <Setter Property="Height" Value="20"/>
        <Setter Property="Width" Value="250"/>
        <Setter Property="HorizontalAlignment" Value="Left"/>
        <Setter Property="Background" Value="#808080"/>
      </Style>
    </Window.Resources>
    <StackPanel Background="LightGray">
	    <custom:MyButtonSimple Name="mybtnsimple" Tap="TapHandler">Click to see Tap custom event work</custom:MyButtonSimple>
    </StackPanel>
</Window>

Tunneling events are created the same way, but with RoutingStrategy set to Tunnel in the registration call. By convention, tunneling events in WPF are prefixed with the word "Preview".

To view the complete sample, including the implementation of the actual "Tap" event handler, see Custom Routed Events Sample. To see an example of how bubbling events work, see How to: Handle a Routed Event.

System.Object
  System.EventArgs
    System.Windows.RoutedEventArgs
      System.Windows.Controls.CleanUpVirtualizedItemEventArgs
      System.Windows.Controls.ContextMenuEventArgs
      System.Windows.Controls.InkCanvasGestureEventArgs
      System.Windows.Controls.InkCanvasStrokeCollectedEventArgs
      System.Windows.Controls.Primitives.DragCompletedEventArgs
      System.Windows.Controls.Primitives.DragDeltaEventArgs
      System.Windows.Controls.Primitives.DragStartedEventArgs
      System.Windows.Controls.Primitives.ScrollEventArgs
      System.Windows.Controls.ScrollChangedEventArgs
      System.Windows.Controls.SelectionChangedEventArgs
      System.Windows.Controls.TextChangedEventArgs
      System.Windows.Controls.ToolTipEventArgs
      System.Windows.Controls.ValidationErrorEventArgs
      System.Windows.Data.DataTransferEventArgs
      System.Windows.DataObjectEventArgs
      System.Windows.DragEventArgs
      System.Windows.ExceptionRoutedEventArgs
      System.Windows.GiveFeedbackEventArgs
      System.Windows.Input.AccessKeyPressedEventArgs
      System.Windows.Input.CanExecuteRoutedEventArgs
      System.Windows.Input.ExecutedRoutedEventArgs
      System.Windows.Input.InputEventArgs
      System.Windows.MediaScriptCommandRoutedEventArgs
      System.Windows.Navigation.RequestNavigateEventArgs
      System.Windows.QueryContinueDragEventArgs
      System.Windows.RequestBringIntoViewEventArgs
      System.Windows.RoutedPropertyChangedEventArgs<T>
      System.Windows.SizeChangedEventArgs
      System.Windows.SourceChangedEventArgs
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0
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