Automation.RemoveAutomationEventHandler(AutomationEvent, AutomationElement, AutomationEventHandler) 方法

定义

移除指定的 UI 自动化UI Automation事件处理程序。Removes the specified UI 自动化UI Automation event handler.

public:
 static void RemoveAutomationEventHandler(System::Windows::Automation::AutomationEvent ^ eventId, System::Windows::Automation::AutomationElement ^ element, System::Windows::Automation::AutomationEventHandler ^ eventHandler);
public static void RemoveAutomationEventHandler (System.Windows.Automation.AutomationEvent eventId, System.Windows.Automation.AutomationElement element, System.Windows.Automation.AutomationEventHandler eventHandler);
static member RemoveAutomationEventHandler : System.Windows.Automation.AutomationEvent * System.Windows.Automation.AutomationElement * System.Windows.Automation.AutomationEventHandler -> unit
Public Shared Sub RemoveAutomationEventHandler (eventId As AutomationEvent, element As AutomationElement, eventHandler As AutomationEventHandler)

参数

eventId
AutomationEvent

事件标识符。An event identifier.

element
AutomationElement

将移除其上的事件处理程序的 UI 自动化UI Automation元素。The UI 自动化UI Automation element on which to remove the event handler.

eventHandler
AutomationEventHandler

传递到指定事件标识符和 UI 自动化UI Automation元素的 AddAutomationEventHandler(AutomationEvent, AutomationElement, TreeScope, AutomationEventHandler) 的处理程序方法。The handler method that was passed to AddAutomationEventHandler(AutomationEvent, AutomationElement, TreeScope, AutomationEventHandler) for the specified event identifier and UI 自动化UI Automation element.

示例

下面的示例代码演示了要添加和删除的事件处理程序。The following example code shows an event handler being added and removed.

// Member variables.
AutomationElement ElementSubscribeButton;
AutomationEventHandler UIAeventHandler;

/// <summary>
/// Register an event handler for InvokedEvent on the specified element.
/// </summary>
/// <param name="elementButton">The automation element.</param>
public void SubscribeToInvoke(AutomationElement elementButton)
{
    if (elementButton != null)
    {
        Automation.AddAutomationEventHandler(InvokePattern.InvokedEvent,
             elementButton, TreeScope.Element,
             UIAeventHandler = new AutomationEventHandler(OnUIAutomationEvent));
        ElementSubscribeButton = elementButton;
    }
}

/// <summary>
/// AutomationEventHandler delegate.
/// </summary>
/// <param name="src">Object that raised the event.</param>
/// <param name="e">Event arguments.</param>
private void OnUIAutomationEvent(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 == InvokePattern.InvokedEvent)
    {
        // TODO Add handling code.
    }
    else
    {
        // TODO Handle any other events that have been subscribed to.
    }
}

private void ShutdownUIA()
{
    if (UIAeventHandler != null)
    {
        Automation.RemoveAutomationEventHandler(InvokePattern.InvokedEvent,
            ElementSubscribeButton, UIAeventHandler);
    }
}
' Member variables.
Private ElementSubscribeButton As AutomationElement
Private UIAeventHandler As AutomationEventHandler


''' <summary>
''' Register an event handler for InvokedEvent on the specified element.
''' </summary>
''' <param name="elementButton">The automation element.</param>
Public Sub SubscribeToInvoke(ByVal elementButton As AutomationElement)
    If (elementButton IsNot Nothing) Then
        UIAeventHandler = New AutomationEventHandler(AddressOf OnUIAutomationEvent)
        Automation.AddAutomationEventHandler(InvokePattern.InvokedEvent, elementButton, _
        TreeScope.Element, UIAeventHandler)
        ElementSubscribeButton = elementButton
    End If

End Sub


''' <summary>
''' AutomationEventHandler delegate.
''' </summary>
''' <param name="src">Object that raised the event.</param>
''' <param name="e">Event arguments.</param>
Private Sub OnUIAutomationEvent(ByVal src As Object, ByVal e As AutomationEventArgs)
    ' Make sure the element still exists. Elements such as tooltips can disappear
    ' before the event is processed.
    Dim sourceElement As AutomationElement
    Try
        sourceElement = DirectCast(src, AutomationElement)
    Catch ex As ElementNotAvailableException
        Exit Sub
    End Try
    If e.EventId Is InvokePattern.InvokedEvent Then
        ' TODO Add handling code.
    Else
    End If
    ' TODO Handle any other events that have been subscribed to.
    Console.WriteLine("Event: " & e.EventId.ProgrammaticName)
End Sub

Private Sub ShutdownUIA()
    If (UIAeventHandler IsNot Nothing) Then
        Automation.RemoveAutomationEventHandler(InvokePattern.InvokedEvent, ElementSubscribeButton, UIAeventHandler)
    End If

End Sub

适用于

另请参阅