Automation.AddAutomationFocusChangedEventHandler Method
Definition
Important
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Registers a method that will handle focus-changed events.
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)
Parameters
- eventHandler
- AutomationFocusChangedEventHandler
The method to call when the event occurs.
Examples
The following example shows this method being used to add an event handler for focus changes.
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
Remarks
Focus-changed events are system-wide; you cannot set a narrower scope.
eventHandler
can be an instance of the method, or a reference to the method (AddressOf
in Visual Basic).
Applies to
See also
- RemoveAutomationFocusChangedEventHandler(AutomationFocusChangedEventHandler)
- AddAutomationEventHandler(AutomationEvent, AutomationElement, TreeScope, AutomationEventHandler)
- AddAutomationPropertyChangedEventHandler(AutomationElement, TreeScope, AutomationPropertyChangedEventHandler, AutomationProperty[])
- AddStructureChangedEventHandler(AutomationElement, TreeScope, StructureChangedEventHandler)
- Subscribe to UI Automation Events
- UI Automation Events Overview
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