Events

Updated on Sep 24, 2025

This article lists the events specific for the RadTabControl control.

• PreviewTabClosed: Occurs when a RadTabItem is about to be closed. The event arguments are of type PreviewTabChangedEventArgs and provide access to the following properties:

  • TabItem: The RadTabItem that has been changed.

  • DataContext: The DataContext of the changed RadTabItem.

    Example 1: PreviewTabClosed Event Handler

    C#

    	private void TabControl_PreviewTabClosed(object sender, Telerik.Windows.Controls.PreviewTabChangedEventArgs e)
    	{
    		if (e.TabItem.Header.ToString() == "Tab 1")
    		{
    			e.Cancel = true;
    		}
    	}

    VB.NET

    	Private Sub TabControl_PreviewTabClosed(ByVal sender As Object, ByVal e As Telerik.Windows.Controls.PreviewTabChangedEventArgs)
    		If e.TabItem.Header.ToString() = "Tab 1" Then
    			e.Cancel = True
    		End If
    	End Sub

• TabClosed: Occurs when a RadTabItem is closed. The event arguments are of type TabChangedEventArgs and expose the following members:

  • TabItem: The RadTabItem that has been changed.

  • DataContext: The DataContext of the changed TabItem.

• PreviewTabUnpinned: Occurs when a RadTabItem is about to be unpinned. Event arguments are of of type PreviewTabChangedEventArgs.

  Example 2: PreviewTabUnpinned Event Handler

  C#

  	private void RadTabControl_PreviewTabUnpinned(object sender, Telerik.Windows.Controls.PreviewTabChangedEventArgs e)
  	{
  		MessageBox.Show($"{e.TabItem.Header} is about to be unpinned.");
  	}

  VB.NET

  	Private Sub RadTabControl_PreviewTabUnpinned(ByVal sender As Object, ByVal e As Telerik.Windows.Controls.PreviewTabChangedEventArgs)
  		MessageBox.Show($"{e.TabItem.Header} is about to be unpinned.")
  	End Sub

• TabUnpinned: Occurs when a RadTabItem is unpinned. The event arguments are of type TabChangedEventArgs.

• PreviewTabPinned: Occurs when a RadTabItem is about to be pinned. The event arguments are of type PreviewTabChangedEventArgs.

  Example 3: PreviewTabPinned Event Handler

  C#

  	private void RadTabControl_PreviewTabPinned(object sender, Telerik.Windows.Controls.PreviewTabChangedEventArgs e)
  	{
  		e.Cancel = true;
  	}

  VB.NET

  	Private Sub RadTabControl_PreviewTabPinned(ByVal sender As Object, ByVal e As Telerik.Windows.Controls.PreviewTabChangedEventArgs)
  		e.Cancel = True
  	End Sub

• TabPinned: Occurs when a RadTabItem is pinned. The event arguments are of type TabChangedEventArgs.

• DropDownOpened: An event that is raised when the Telerik.Windows.Controls.TabControl.DropDownMenu is opened. This is a RoutedEvent. The event arguments are of type DropDownEventArgs and expose the following members:

  • DropDownItemsSource: Gets or sets the items collection for the drop down context menu.

  • RoutedEvent: Gets or sets the RoutedEventAgs.RoutedEvent associated with this RoutedEventArgs instance.

    Example 4: DropDownOpened Routed Event

    C#

    	private void RadTabControl_DropDownOpened(object sender, DropDownEventArgs e)
    	{
    		List<string> dropDownItems = e.DropDownItemsSource.Cast<string>().ToList<string>();
    		dropDownItems.Add("New DropDown Item.");
    		e.DropDownItemsSource = dropDownItems;
    	}

    VB.NET

    	Private Sub RadTabControl_DropDownOpened(ByVal sender As Object, ByVal e As DropDownEventArgs)
    		Dim dropDownItems As List(Of String) = e.DropDownItemsSource.Cast(Of String)().ToList(Of String)()
    		dropDownItems.Add("New DropDown Item.")
    		e.DropDownItemsSource = dropDownItems
    	End Sub

• DropDownClosed: This event is raised when the Telerik.Windows.Controls.TabControl.DropDownMenu is closed. This is a RoutedEvent. The event arguments are of type DropDownEventArgs.

• ItemReordered: This event occurs when an item is reordered while dragging. This is a RoutedEvent. In order for this event to be raised, the AllowDragReorder property needs to be set to True. The event arguments are of type ItemReorderedEventArgs and expose the following members:

  • OldIndex: Gets the previous index of the dragged item.

  • NewIndex: Gets the next index of the dragged item.