Assembly: System.Windows (in System.Windows.dll)
'Declaration Public Sub RemoveHandler ( _ routedEvent As RoutedEvent, _ handler As Delegate _ )
routedEvent or handler is Nothing.
routedEvent does not represent a supported routed event.
handler does not implement a supported delegate.
Attempted to remove handler for an event not supported by the current platform variation.
can only be used for the event handlers of the events that are supported by AddHandler. You cannot use to remove handlers for general events that are added with the language-specific event wiring syntax (such as += in C#) or with event attribute in XAML. You should instead use language-specific event handler disconnection / removal syntax (such as -= in C#) for such event handlers.
Calling this method has no effect if there were no handlers registered with criteria that match the input parameters for the method call.
If more than one handler is attached that matched the criteria, only the first handler in the event handler store is removed. This behavior is consistent with CLR behavior of the -= operator.
Neither routedEvent nor handler may be Nothing. Attempting to provide either value as Nothing will raise an exception.
This method ignores the handledEventsToo parameter information of the symmetric AddHandler call.