AutomationEventHandler 代理人

定義

命名空間:

System.Windows.Automation

組件:

UIAutomationTypes.dll

代表使用者介面自動化用戶端應用程式所實作，用以處理使用者介面自動化提供者所引發之事件的方法。

public delegate void AutomationEventHandler(System::Object ^ sender, AutomationEventArgs ^ e);

public delegate void AutomationEventHandler(object sender, AutomationEventArgs e);

type AutomationEventHandler = delegate of obj * AutomationEventArgs -> unit

Public Delegate Sub AutomationEventHandler(sender As Object, e As AutomationEventArgs)

參數

sender

Object

引發事件的物件。

e

AutomationEventArgs

事件相關資訊。

範例

下列範例示範如何訂閱及處理事件。

// 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

備註

AutomationEventHandler使用委派來指定用戶端呼叫的方法，以處理消費者介面自動化事件。

AutomationElement所 sender 表示的 可能沒有任何快取的屬性或模式，視應用程式是否在作用中時 CacheRequest 訂閱此事件而定。

擴充方法

另請參閱

• AddAutomationEventHandler(AutomationEvent, AutomationElement, TreeScope, AutomationEventHandler)
• RemoveAutomationEventHandler(AutomationEvent, AutomationElement, AutomationEventHandler)
• AutomationEventArgs
• 訂閱 UI 自動化事件
• UI 自動化事件概觀