The following example demonstrates how to provide value-changed handlers for the SelectedItem and SelectedIndex dependency properties in order to be notified when their value changes.

Dim selectedItemDescriptor As DependencyPropertyDescriptor = DependencyPropertyDescriptor.FromProperty( DataGridControl.SelectedItemProperty, GetType( DataGridControl ) )
selectedItemDescriptor.AddValueChanged( Me.EmployeesGrid, Me.SelectedItemChanged )

DependencyPropertyDescriptor selectedItemDescriptor = DependencyPropertyDescriptor.FromProperty( DataGridControl.SelectedItemProperty, typeof( DataGridControl ) );
selectedItemDescriptor.AddValueChanged( this.EmployeesGrid, this.SelectedItemChanged );

The SelectedItems property is also a dependency property; however, using a value-changed handler will not function in this case since the values of the collection are modified and not the collection itself. Although the SelectedItems property is exposed as an IList it is actually an ObservableCollection; therefore, in order to be notified when its content (i.e., the items that are selected) changes, it can be cast as an INotifyCollectionChanged and subscribe to its CollectionChanged event.

AddHandler CType( Me.EmployeesGrid.SelectedItems, INotifyCollectionChanged ).CollectionChanged, AddressOf Me.Window1_CollectionChanged

( ( INotifyCollectionChanged )this.EmployeesGrid.SelectedItems ).CollectionChanged += new NotifyCollectionChangedEventHandler( Window1_CollectionChanged );