Assembly: WindowsBase (in WindowsBase.dll)
The call stack is not unwound at this point (first-chance exception).
Event handlers for this event must be written with care to avoid creating secondary exceptions and to catch any that occur. It is recommended to avoid allocating memory or doing any resource intensive operations in the handler.
The event provides a means to not raise the UnhandledException event. The event is raised first, and If RequestCatch on the DispatcherUnhandledExceptionFilterEventArgs is set to false, the UnhandledException event will not be raised.