WindowPattern.WindowClosedEvent Field

///-------------------------------------------------------------------- 
/// <summary> 
/// Register for events of interest. 
/// </summary> 
/// <param name="targetControl">
/// The automation element of interest. 
/// </param> 
///-------------------------------------------------------------------- 
private void RegisterForAutomationEvents(
    AutomationElement targetControl)
{
    AutomationEventHandler eventHandler = 
        new AutomationEventHandler(OnWindowOpenOrClose);
    Automation.AddAutomationEventHandler(
        WindowPattern.WindowClosedEvent, 
        targetControl, TreeScope.Element, eventHandler);
    Automation.AddAutomationEventHandler(
        WindowPattern.WindowOpenedEvent, 
        targetControl, TreeScope.Element, eventHandler);
}

///-------------------------------------------------------------------- 
/// <summary> 
/// AutomationEventHandler delegate. 
/// </summary> 
/// <param name="src">Object that raised the event.</param>
/// <param name="e">Event arguments.</param>
///-------------------------------------------------------------------- 
private void OnWindowOpenOrClose(object src, AutomationEventArgs e)
{
    // Make sure the element still exists. Elements such as tooltips 
    // can disappear before the event is processed.
    AutomationElement sourceElement;
    try
    {
        sourceElement = src as AutomationElement;
    }
    catch (ElementNotAvailableException)
    {
        return;
    }

    if (e.EventId == WindowPattern.WindowOpenedEvent)
    {
        // TODO: event handling 
        return;
    }
    if (e.EventId == WindowPattern.WindowClosedEvent)
    {
        // TODO: event handling 
        return;
    }
}