public static IObservable <EventPattern <TEventArgs> > RoutedEventRaised <TDelegate, TEventArgs>(
this UIElement element,
RoutedEvent @event,
bool handledEventsToo)
where TEventArgs : RoutedEventArgs
{
Contract.Requires(element != null);
Contract.Requires(@event != null);
Contract.Ensures(Contract.Result <IObservable <EventPattern <TEventArgs> > >() != null);
return(Observable.Create <EventPattern <TEventArgs> >(
observer =>
{
RoutedEventHandler handler = (sender, e) => observer.OnNext(new EventPattern <TEventArgs>(sender, (TEventArgs)e));
#if UNIVERSAL
var d = handler.GetMethodInfo().CreateDelegate(typeof(TDelegate), handler.Target);
#else
var d = Delegate.CreateDelegate(typeof(TDelegate), handler.Target, handler.Method);
#endif
/* Silverlight throws an ArgumentException with the word "handler" as the message if the handler is
* not the exact type used by the specified routed event. Therefore, it is necessary for this extension
* method to have a TDelegate type parameter so that it can create the proper handler type via reflection.
*
* TODO: Already tested for WP 7.1 but not tested yet for WP 8.0, so TDelegate might not be required anymore.
*/
element.AddHandler(@event, d, handledEventsToo);
return Disposable.Create(() => element.RemoveHandler(@event, d));
}));
}
