Automation.AddStructureChangedEventHandler Metod

Definition

Namnområde:
System.Windows.Automation
Sammansättning:
UIAutomationClient.dll

Registrerar den metod som ska hantera strukturändringshändelser.

public:
 static void AddStructureChangedEventHandler(System::Windows::Automation::AutomationElement ^ element, System::Windows::Automation::TreeScope scope, System::Windows::Automation::StructureChangedEventHandler ^ eventHandler);
public static void AddStructureChangedEventHandler(System.Windows.Automation.AutomationElement element, System.Windows.Automation.TreeScope scope, System.Windows.Automation.StructureChangedEventHandler eventHandler);
static member AddStructureChangedEventHandler : System.Windows.Automation.AutomationElement * System.Windows.Automation.TreeScope * System.Windows.Automation.StructureChangedEventHandler -> unit
Public Shared Sub AddStructureChangedEventHandler (element As AutomationElement, scope As TreeScope, eventHandler As StructureChangedEventHandler)

Parametrar

element
AutomationElement

Det UI Automation element som händelsehanteraren ska associeras med.

scope
TreeScope

Omfattningen av händelser som ska hanteras. det vill: om de är på själva elementet, eller på dess förfäder och ättlingar.

eventHandler
StructureChangedEventHandler

Den metod som ska anropas när den struktur ändrade händelsen inträffar.

Exempel

I följande exempel visas ett strukturändringarat händelsehanterardelegat som anropas när underträdet för de angivna AutomationElement ändringarna.

/// <summary>
/// Handles structure-changed events. If a new app window has been added, this method ensures
/// it's in the list of runtime IDs and subscribed to window-close events.
/// </summary>
/// <param name="sender">Object that raised the event.</param>
/// <param name="e">Event arguments.</param>
/// <remarks>
/// An exception can be thrown by the UI Automation core if the element disappears
/// before it can be processed -- for example, if a menu item is only briefly visible. 
/// This exception cannot be caught here because it crosses native/managed boundaries. 
/// In the debugger, you can ignore it and continue execution. The exception does not cause
/// a break when the executable is being run.
/// </remarks>
private void OnStructureChanged(object sender, StructureChangedEventArgs e)
{
    AutomationElement element = sender as AutomationElement;

    if (e.StructureChangeType == StructureChangeType.ChildAdded)
    {
        Object windowPattern;
        if (false == element.TryGetCurrentPattern(WindowPattern.Pattern, out windowPattern))
        {
            return;
        }
        int[] rid = e.GetRuntimeId();
        if (RuntimeIdListed(rid, savedRuntimeIds) < 0)
        {
            AddToWindowHandler(element);
            savedRuntimeIds.Add(rid);
        }
    }
}

''' <summary>
''' Handles structure-changed events. If a new app window has been added, this method ensures
''' it's in the list of runtime IDs and subscribed to window-close events.
''' </summary>
''' <param name="sender">Object that raised the event.</param>
''' <param name="e">Event arguments.</param>
''' <remarks>
''' An exception can be thrown by the UI Automation core if the element disappears
''' before it can be processed -- for example, if a menu item is only briefly visible. 
''' This exception cannot be caught here because it crosses native/managed boundaries. 
''' In the debugger, you can ignore it and continue execution. The exception does not cause
''' a break when the executable is being run.
''' </remarks>
Private Sub OnStructureChanged(ByVal sender As Object, ByVal e As StructureChangedEventArgs) 

    Dim element As AutomationElement = DirectCast(sender, AutomationElement)
    If e.StructureChangeType = StructureChangeType.ChildAdded Then
        Dim myWindowPattern As Object = Nothing
        If False = element.TryGetCurrentPattern(WindowPattern.Pattern, myWindowPattern) Then
            Return
        End If
        Dim rid As Integer() = e.GetRuntimeId()
        If RuntimeIdListed(rid, savedRuntimeIds) < 0 Then
            AddToWindowHandler(element)
            savedRuntimeIds.Add(rid)
        End If
    End If
 
End Sub

Följande exempelkod lägger till en instans av ombudet.

// elementRoot is an AutomationElement.
Automation.AddStructureChangedEventHandler(elementRoot, TreeScope.Children, 
    new StructureChangedEventHandler(OnStructureChanged));

' elementRoot is an AutomationElement.
Automation.AddStructureChangedEventHandler(elementRoot, TreeScope.Children, New StructureChangedEventHandler(AddressOf OnStructureChanged))

Kommentarer

eventHandler kan vara en instans av metoden eller en referens till metoden (AddressOf i Visual Basic).

Gäller för

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