Handling collection-changed events

The following example demonstrates how to subscribe to the CollectionChanged event of the DataGridCollectionView.SortDescriptions collection's INotifyCollectionChanged interface implementation to be notified when sorting applied to a grid's columns changes.

C#

  protected override void OnInitialized( EventArgs e )
  {
    base.OnInitialized( e ); 
    DataGridCollectionView view = this.OrdersGrid.ItemsSource as DataGridCollectionView;
    ( ( INotifyCollectionChanged )view.SortDescriptions ).CollectionChanged +=
                                        new NotifyCollectionChangedEventHandler( this.SortCollectionChanged );
  } 
  private void SortCollectionChanged( object sender, NotifyCollectionChangedEventArgs e )
  {
    Debug.WriteLine( "Sort changed" );
  }

VB.NET

  Protected Overrides Sub OnInitialized(ByVal e As EventArgs)
    MyBase.OnInitialized(e)

    Dim view As DataGridCollectionView = TryCast(Me.OrdersGrid.ItemsSource, DataGridCollectionView)
    AddHandler (CType(view.SortDescriptions, INotifyCollectionChanged)).CollectionChanged,
                                            AddressOf SortCollectionChanged
  End Sub
  Private Sub SortCollectionChanged(ByVal sender As Object, ByVal e As NotifyCollectionChangedEventArgs)
    Debug.WriteLine("Sort changed")
  End Sub