/// <summary> /// Provides a secure method for setting the Behaviors property. /// This dependency property indicates .... /// </summary> private static void SetBehaviors(DependencyObject d, BehaviorBindingCollection value) { d.SetValue(BehaviorsPropertyKey, value); INotifyCollectionChanged collection = (INotifyCollectionChanged)value; collection.CollectionChanged += new NotifyCollectionChangedEventHandler(CollectionChanged); }
/// <summary> /// Gets the Behaviors property. /// Here we initialze the collection and set the Owner property /// </summary> public static BehaviorBindingCollection GetBehaviors(DependencyObject d) { if (d == null) { throw new InvalidOperationException("The dependency object trying to attach to is set to null"); } BehaviorBindingCollection collection = d.GetValue(CommandBehaviorCollection.BehaviorsProperty) as BehaviorBindingCollection; if (collection == null) { collection = new BehaviorBindingCollection(); collection.Owner = d; SetBehaviors(d, collection); } return(collection); }
static void CollectionChanged(object sender, NotifyCollectionChangedEventArgs e) { BehaviorBindingCollection sourceCollection = (BehaviorBindingCollection)sender; switch (e.Action) { //when an item(s) is added we need to set the Owner property implicitly case NotifyCollectionChangedAction.Add: { if (e.NewItems != null) { foreach (BehaviorBinding item in e.NewItems) { item.Owner = sourceCollection.Owner; } } break; } //when an item(s) is removed we should Dispose the BehaviorBinding case NotifyCollectionChangedAction.Remove: { if (e.OldItems != null) { foreach (BehaviorBinding item in e.OldItems) { item.Behavior.Dispose(); } } break; } //here we have to set the owner property to the new item and unregister the old item case NotifyCollectionChangedAction.Replace: { if (e.NewItems != null) { foreach (BehaviorBinding item in e.NewItems) { item.Owner = sourceCollection.Owner; } } if (e.OldItems != null) { foreach (BehaviorBinding item in e.OldItems) { item.Behavior.Dispose(); } } break; } //when an item(s) is removed we should Dispose the BehaviorBinding case NotifyCollectionChangedAction.Reset: { if (e.OldItems != null) { foreach (BehaviorBinding item in e.OldItems) { item.Behavior.Dispose(); } } break; } case NotifyCollectionChangedAction.Move: default: break; } }