Assembly: System.Windows (in System.Windows.dll)
In the existing Silverlight implementation, INotifyCollectionChanged is always used for single item changes. Because of the NotifyCollectionChangedEventArgs constructor signatures, it is not possible to raise CollectionChanged in such a way that it reports multiple items.
The type of this property is IList for compatibility, but in the existing Silverlight implementation you can generally assume that the IList only contains one item. To get that item you could use the C# shorthand of collectionChangedEventArgs.OldItems.
will contain the following depending on the Action being reported in the event data:
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.