Automation.AddAutomationFocusChangedEventHandler Methode

Definition

Registriert eine Methode, die Fokusänderungsereignisse behandelt.

public:
 static void AddAutomationFocusChangedEventHandler(System::Windows::Automation::AutomationFocusChangedEventHandler ^ eventHandler);
public static void AddAutomationFocusChangedEventHandler (System.Windows.Automation.AutomationFocusChangedEventHandler eventHandler);
static member AddAutomationFocusChangedEventHandler : System.Windows.Automation.AutomationFocusChangedEventHandler -> unit
Public Shared Sub AddAutomationFocusChangedEventHandler (eventHandler As AutomationFocusChangedEventHandler)

Parameter

eventHandler
AutomationFocusChangedEventHandler

Die Methode, die beim Eintreten des Ereignisses aufgerufen werden soll.

Beispiele

Das folgende Beispiel zeigt, wie diese Methode verwendet wird, um einen Ereignishandler für Fokusänderungen hinzuzufügen.

AutomationFocusChangedEventHandler focusHandler = null;

/// <summary>
/// Create an event handler and register it.
/// </summary>
public void SubscribeToFocusChange()
{
    focusHandler = new AutomationFocusChangedEventHandler(OnFocusChange);
    Automation.AddAutomationFocusChangedEventHandler(focusHandler);
}

/// <summary>
/// Handle the event.
/// </summary>
/// <param name="src">Object that raised the event.</param>
/// <param name="e">Event arguments.</param>
private void OnFocusChange(object src, AutomationFocusChangedEventArgs e)
{
    // TODO Add event handling code.
    // The arguments tell you which elements have lost and received focus.
}

/// <summary>
/// Cancel subscription to the event.
/// </summary>
public void UnsubscribeFocusChange()
{
    if (focusHandler != null)
    {
        Automation.RemoveAutomationFocusChangedEventHandler(focusHandler);
    }
}
Private focusHandler As AutomationFocusChangedEventHandler = Nothing


''' <summary>
''' Create an event handler and register it.
''' </summary>
Public Sub SubscribeToFocusChange()
    focusHandler = New AutomationFocusChangedEventHandler(AddressOf OnFocusChange)
    Automation.AddAutomationFocusChangedEventHandler(focusHandler)

End Sub


''' <summary>
''' Handle the event.
''' </summary>
''' <param name="src">Object that raised the event.</param>
''' <param name="e">Event arguments.</param>
Private Sub OnFocusChange(ByVal src As Object, ByVal e As AutomationFocusChangedEventArgs)

End Sub

' TODO Add event handling code.
' The arguments tell you which elements have lost and received focus.

''' <summary>
''' Cancel subscription to the event.
''' </summary>
Public Sub UnsubscribeFocusChange()
    If (focusHandler IsNot Nothing) Then
        Automation.RemoveAutomationFocusChangedEventHandler(focusHandler)
    End If

End Sub

Hinweise

Fokusänderungsereignisse sind systemweit; Sie können keinen schmaleren Bereich festlegen.

eventHandlerkann eine Instanz der Methode oder ein Verweis auf die Methode (AddressOf in Visual Basic) sein.

Gilt für

Siehe auch