private static void OnEventNameChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
{
EventTriggerBehaviorBase behavior = (EventTriggerBehaviorBase)dependencyObject;
if (behavior.AssociatedObject == null || behavior.resolvedSource == null)
{
return;
}
string oldEventName = (string)args.OldValue;
string newEventName = (string)args.NewValue;
behavior.UnregisterEvent(oldEventName);
behavior.RegisterEvent(newEventName);
}
private void RegisterEvent(string eventName)
{
if (string.IsNullOrEmpty(eventName))
{
return;
}
if (eventName != "Loaded")
{
var sourceObjectType = this.resolvedSource.GetType();
var info = sourceObjectType.GetRuntimeEvent(eventName);
if (info == null)
{
throw new ArgumentException(string.Format(
"Can not find event {0} for the class {1}",
this.EventName,
sourceObjectType.Name));
}
var methodInfo = typeof(EventTriggerBehaviorBase).GetTypeInfo().GetDeclaredMethod("OnEvent");
this.eventHandler = methodInfo.CreateDelegate(info.EventHandlerType, this);
this.isWindowsRuntimeEvent = EventTriggerBehaviorBase.IsWindowsRuntimeEvent(info);
if (this.isWindowsRuntimeEvent)
{
this.addEventHandlerMethod = add => (EventRegistrationToken)info.AddMethod.Invoke(this.resolvedSource, new object[] { add });
this.removeEventHandlerMethod = token => info.RemoveMethod.Invoke(this.resolvedSource, new object[] { token });
WindowsRuntimeMarshal.AddEventHandler(this.addEventHandlerMethod, this.removeEventHandlerMethod, this.eventHandler);
}
else
{
info.AddEventHandler(this.resolvedSource, this.eventHandler);
}
}
else if (!this.isLoadedEventRegistered)
{
var element = this.resolvedSource as FrameworkElement;
if (element != null && !EventTriggerBehaviorBase.IsElementLoaded(element))
{
this.isLoadedEventRegistered = true;
element.Loaded += this.OnEvent;
}
}
}
private static bool IsWindowsRuntimeEvent(EventInfo eventInfo)
{
return(eventInfo != null &&
EventTriggerBehaviorBase.IsWindowsRuntimeType(eventInfo.EventHandlerType) &&
EventTriggerBehaviorBase.IsWindowsRuntimeType(eventInfo.DeclaringType));
}
private static void OnSourceObjectChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
{
EventTriggerBehaviorBase behavior = (EventTriggerBehaviorBase)dependencyObject;
behavior.SetResolvedSource(behavior.ComputeResolvedSource());
}