RoutedEvent.cs

// This event uses the bubbling routing strategy
              public static readonly RoutedEvent CheckedEvent = EventManager.RegisterRoutedEvent(
                     "Checked", RoutingStrategy.Bubble, typeof(RoutedEventHandler), typeof(TreeView));
  
              public static void AddCheckedHandler(DependencyObject d, RoutedEventHandler handler)
              {
                     UIElement uie = d as UIElement;
                     if (uie != null)
                     {
                           uie.AddHandler(CheckedTreeViewItem.CheckedEvent, handler);
                     }
              }
              public static void RemoveCheckedHandler(DependencyObject d, RoutedEventHandler handler)
              {
                     UIElement uie = d as UIElement;
                     if (uie != null)
                     {
                           uie.RemoveHandler(CheckedTreeViewItem.CheckedEvent, handler);
                     }
              }
 }