System.Windows.Controls.ItemsControl.OnItemsSourceChanged C# (CSharp) Méthode

		internal virtual void OnItemsSourceChanged (IEnumerable oldSource, IEnumerable newSource)
		{
			if (CollectionListener != null) {
				CollectionListener.Detach ();
				CollectionListener = null;
			}

			if (newSource != null) {
				if (newSource is INotifyCollectionChanged) {
					CollectionListener = new WeakCollectionChangedListener (((INotifyCollectionChanged)newSource), this);
				}
				
				Items.ClearImpl ();
				Items.SetIsReadOnly (true);
				itemsIsDataBound = true;
				
				foreach (var v in newSource)
					Items.AddImpl (v);
				
				// Setting itemsIsDataBound to true prevents normal notifications from propagating, so do it manually here
				OnItemsChanged (new NotifyCollectionChangedEventArgs (NotifyCollectionChangedAction.Reset));
			} else {
				itemsIsDataBound = false;
				Items.SetIsReadOnly (false);		
				Items.ClearImpl ();
			}
			// Yes this is stupid and shouldn't be here, but DRT 348 sets an empty collection as the ItemsSource
			// and expects the LayoutUpdated event to be raised. This is the only way that makes sense for this
			// to happen. It's all very strange.
			InvalidateMeasure ();
		}