When a collection view implements the IEditableCollectionView interface, you can directly change the underlying collection, if it allows changes to be made, by using the methods and properties that IEditableCollectionView exposes, regardless of the collection's type.

The types ItemCollection, BindingListCollectionView, and ListCollectionView are the types that ship with Windows Presentation Foundation (WPF) that inherit from CollectionView. These types also implement the IEditableCollectionView, so you can edit a collection that uses one of those types. ItemCollection, in particular, is often used because the ItemsControl..::.Items property is an ItemCollection.

The following example shows how to add an item to a collection by using methods that are defined by IEditableCollectionView. This application displays a list of items for sale and gives the user the option of adding, editing, or removing an item. When the user adds or edits an item, a form prompts the user to enter a new item. If the user submits the form, the item is committed to the collection. If the user cancels the form, the item is discarded. For the entire sample, see Changing a Collection by Using IEditableCollectionView Sample.

IEditableCollectionView editableCollectionView = 
    itemsControl.Items as IEditableCollectionView; 

if (!editableCollectionView.CanAddNew)
{
    MessageBox.Show("You cannot add items to the list.");
    return;
}

// Create a window that prompts the user to enter a new
// item to sell.
ChangeItemWindow win = new ChangeItemWindow();

//Create a new item to be added to the collection.
win.DataContext = editableCollectionView.AddNew();

// If the user submits the new item, commit the new
// object to the collection.  If the user cancels 
// adding the new item, discard the new item.
if ((bool)win.ShowDialog())
{
    editableCollectionView.CommitNew();
}
else
{
    editableCollectionView.CancelNew();
}

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

.NET Framework

Reference