Gets or sets the RoutedEventArgs instance.associated with this
Assembly: PresentationCore (in PresentationCore.dll)
Attempted to change thevalue while the event is being routed.
You cannot set this value on a RoutedEventArgs that has already been routed (for instance, if you obtained the arguments through a handler). Attempting to do so will generate an exception. You can only set it on an instance that has not yet been used to generate an invocation of the event.
The value ofcannot be null at any time.
Available since 3.0