Describes the action that caused a CollectionChanged event.
public enum NotifyCollectionChangedAction
One or more items were added to the collection.
The collection has been updated in a batch operation.
An item in the collection has changed.
An item in the collection is about to change.
One or more items were moved within the collection.
One or more items were removed from the collection.
One or more items were replaced in the collection.
The content of the collection changed dramatically.