RoutedPropertyChangingEventHandler<T> Delegate

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Represents methods that handle various routed events that track property values changing. Typically the events denote a cancellable action.

Namespace:  System.Windows.Controls
Assembly:  System.Windows.Controls (in System.Windows.Controls.dll)


Public Delegate Sub RoutedPropertyChangingEventHandler(Of T) ( _
    sender As Object, _
    e As RoutedPropertyChangingEventArgs(Of T) _
public delegate void RoutedPropertyChangingEventHandler<T>(
    Object sender,
    RoutedPropertyChangingEventArgs<T> e

Type Parameters

  • T
    The type of the value for the dependency property that is changing.


  • sender
    Type: System.Object
    The object where the initiating property is changing.


Examples of events that use type-constrained delegates based on RoutedPropertyChangingEventHandler<T> include DropDownClosing and DropDownClosing.

The difference between RoutedPropertyChanged events and RoutedPropertyChanging events is that RoutedPropertyChanging events typically give the application an opportunity to cancel the property change, by setting Cancel to true in the event data.

Version Information


Supported in: 5, 4, 3


For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.