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Automation.AddStructureChangedEventHandler Metoda

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Definice

Obor názvů:
System.Windows.Automation
Sestavení:
UIAutomationClient.dll

Registruje metodu, která bude zpracovávat události změněné struktury.

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)

Parametry

element
AutomationElement

Model UI Automation prvek, ke kterému chcete přidružit obslužnou rutinu události.

scope
TreeScope

Rozsah událostí, které mají být zpracovány; to znamená, zda jsou na samotném prvku, nebo na jeho předcích a potomcích.

eventHandler
StructureChangedEventHandler

Metoda, která se má volat, když dojde ke změně struktury.

Příklady

Následující příklad ukazuje delegáta obslužné rutiny události změněné struktury, který bude volána při každém podstromu zadaných AutomationElement změn.

/// <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

Následující příklad kódu přidá instanci delegáta.

// 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))

Poznámky

eventHandler může být instancí metody nebo odkazem na metodu (AddressOf v jazyce Visual Basic).

Platí pro

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