<ToggleButton Content="Add New..." Click="AddNewSortItem_Click" />

		private void AddNewSortItem_Click(object sender, RoutedEventArgs e)
		{
			FrameworkElement fe = sender as FrameworkElement;
			fe.ContextMenu = new ContextMenu();

			MenuItem mi = new MenuItem();
			mi.Header = "MenuItem";
			mi.Click += new RoutedEventHandler(AddNew_Click);
			fe.ContextMenu.Items.Add(mi);

			fe.ContextMenu.IsOpen = true;
			fe.ContextMenu.Closed += new RoutedEventHandler(ContextMenu_Closed);
		}

		void ContextMenu_Closed(object sender, RoutedEventArgs e)
		{
			btnAdd.IsChecked = false;
		}

		void AddNew_Click(object sender, RoutedEventArgs e)
		{
			MenuItem mi = sender as MenuItem;
			string name = mi.Header.ToString();
		}

WindowInteropHelper wih(MyWindow);
wih.Owner = hWnd;