//////////////////////////////////////////////////////////////////////// // ProcessOneTrigger // // Find the target element for this trigger, and set a listener for // the event into (pointing back to the trigger). internal static void ProcessOneTrigger(FrameworkElement triggersHost, TriggerBase triggerBase) { // This code path is used in the element trigger case. We don't actually // need these guys to be usable cross-thread, so we don't really need // to freeze/seal these objects. The only one expected to cause problems // is a change to the RoutedEvent. At the same time we remove this // Seal(), the RoutedEvent setter will check to see if the handler has // already been created and refuse an update if so. // triggerBase.Seal(); EventTrigger eventTrigger = triggerBase as EventTrigger; if (eventTrigger != null) { Debug.Assert(eventTrigger._routedEventHandler == null && eventTrigger._source == null); // PERF: Cache this result if it turns out we're doing a lot of lookups on the same name. eventTrigger._source = FrameworkElement.FindNamedFrameworkElement(triggersHost, eventTrigger.SourceName); // Create a statefull event delegate (which keeps a ref to the FE). EventTriggerSourceListener listener = new EventTriggerSourceListener(eventTrigger, triggersHost); // Store the RoutedEventHandler & target for use in DisconnectOneTrigger eventTrigger._routedEventHandler = new RoutedEventHandler(listener.Handler); eventTrigger._source.AddHandler(eventTrigger.RoutedEvent, eventTrigger._routedEventHandler, false /* HandledEventsToo */); } else { throw new InvalidOperationException(SR.Get(SRID.TriggersSupportsEventTriggersOnly)); } }
//////////////////////////////////////////////////////////////////////// // ProcessOneTrigger // // Find the target element for this trigger, and set a listener for // the event into (pointing back to the trigger). internal static void ProcessOneTrigger( FrameworkElement triggersHost, TriggerBase triggerBase ) { // This code path is used in the element trigger case. We don't actually // need these guys to be usable cross-thread, so we don't really need // to freeze/seal these objects. The only one expected to cause problems // is a change to the RoutedEvent. At the same time we remove this // Seal(), the RoutedEvent setter will check to see if the handler has // already been created and refuse an update if so. // triggerBase.Seal(); EventTrigger eventTrigger = triggerBase as EventTrigger; if( eventTrigger != null ) { Debug.Assert( eventTrigger._routedEventHandler == null && eventTrigger._source == null); // PERF: Cache this result if it turns out we're doing a lot of lookups on the same name. eventTrigger._source = FrameworkElement.FindNamedFrameworkElement( triggersHost, eventTrigger.SourceName ); // Create a statefull event delegate (which keeps a ref to the FE). EventTriggerSourceListener listener = new EventTriggerSourceListener( eventTrigger, triggersHost ); // Store the RoutedEventHandler & target for use in DisconnectOneTrigger eventTrigger._routedEventHandler = new RoutedEventHandler(listener.Handler); eventTrigger._source.AddHandler( eventTrigger.RoutedEvent, eventTrigger._routedEventHandler, false /* HandledEventsToo */ ); } else { throw new InvalidOperationException(SR.Get(SRID.TriggersSupportsEventTriggersOnly)); } }