private static void OnEventNameChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
{
EventTriggerBehavior behavior = (EventTriggerBehavior)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")
{
Type sourceObjectType = this.resolvedSource.GetType();
EventInfo info = sourceObjectType.GetRuntimeEvent(eventName);
if (info == null)
{
throw new ArgumentException(string.Format(
CultureInfo.CurrentCulture,
ResourceHelper.CannotFindEventNameExceptionMessage,
this.EventName,
sourceObjectType.Name));
}
MethodInfo methodInfo = typeof(EventTriggerBehavior).GetTypeInfo().GetDeclaredMethod("OnEvent");
this.eventHandler = methodInfo.CreateDelegate(info.EventHandlerType, this);
this.isWindowsRuntimeEvent = EventTriggerBehavior.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)
{
FrameworkElement element = this.resolvedSource as FrameworkElement;
if (element != null && !EventTriggerBehavior.IsElementLoaded(element))
{
this.isLoadedEventRegistered = true;
element.Loaded += this.OnEvent;
}
}
}
/// <summary>
/// Executes the action.
/// </summary>
/// <param name="sender">The <see cref="System.Object"/> that is passed to the action by the behavior. Generally this is <seealso cref="Microsoft.Xaml.Interactivity.IBehavior.AssociatedObject"/> or a target object.</param>
/// <param name="parameter">The value of this parameter is determined by the caller.</param>
/// <returns>True if the transition to the specified state succeeds; else false.</returns>
public object Execute(object sender, object parameter)
{
if (string.IsNullOrEmpty(this.StateName))
{
return(false);
}
if (this.ReadLocalValue(GoToStateAction.TargetObjectProperty) != DependencyProperty.UnsetValue)
{
Control control = this.TargetObject as Control;
if (control == null)
{
return(false);
}
return(VisualStateUtilities.GoToState(control, this.StateName, this.UseTransitions));
}
FrameworkElement element = sender as FrameworkElement;
if (element == null || !EventTriggerBehavior.IsElementLoaded(element))
{
return(false);
}
Control resolvedControl = VisualStateUtilities.FindNearestStatefulControl(element);
if (resolvedControl == null)
{
throw new InvalidOperationException(string.Format(
CultureInfo.CurrentCulture,
ResourceHelper.GoToStateActionTargetHasNoStateGroups,
element.Name));
}
return(VisualStateUtilities.GoToState(resolvedControl, this.StateName, this.UseTransitions));
}
private static bool IsWindowsRuntimeEvent(EventInfo eventInfo)
{
return(eventInfo != null &&
EventTriggerBehavior.IsWindowsRuntimeType(eventInfo.EventHandlerType) &&
EventTriggerBehavior.IsWindowsRuntimeType(eventInfo.DeclaringType));
}
private static void OnSourceObjectChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs args)
{
EventTriggerBehavior behavior = (EventTriggerBehavior)dependencyObject;
behavior.SetResolvedSource(behavior.ComputeResolvedSource());
}
