S'abonner à des événements UI Automation
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Cette documentation s'adresse aux développeurs .NET Framework qui veulent utiliser les classes UI Automation managées définies dans l'espace de noms System.Windows.Automation.Pour obtenir les informations les plus récentes sur UI Automation, consultez API Windows Automation : UI Automation (page éventuellement en anglais). |
Cette rubrique montre comment s'abonner à des événements déclenchés par des fournisseurs UI Automation.
Exemple
L'exemple de code suivant enregistre un gestionnaire d'événements pour l'événement déclenché lorsqu'un contrôle tel qu'un bouton est appelé et le supprime lorsque le formulaire d'application se ferme. L'événement est identifié par un AutomationEvent passé en tant que paramètre à AddAutomationEventHandler.
' 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 'SubscribeToInvoke
''' <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 'OnUIAutomationEvent
Private Sub ShutdownUIA()
If (UIAeventHandler IsNot Nothing) Then
Automation.RemoveAutomationEventHandler(InvokePattern.InvokedEvent, ElementSubscribeButton, UIAeventHandler)
End If
End Sub 'ShutdownUIA
// 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);
}
}
L'exemple suivant montre comment utiliser Microsoft UI Automation pour s'abonner à un événement déclenché lorsque le focus est modifié. Le gestionnaire d'événements est annulé dans une méthode qui pourrait être appelée à l'arrêt de l'application ou lorsque la notification des événements de l'interface utilisateur n'est plus requise.
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 'SubscribeToFocusChange
''' <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 'OnFocusChange
' 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 'UnsubscribeFocusChange
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);
}
}