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Suchen eines Benutzeroberflächenautomatisierungs-Elements anhand einer Eigenschaftenbedingung

Hinweis

Diese Dokumentation ist für .NET Framework-Entwickler konzipiert, die die verwalteten Klassen zur Automatisierung der Benutzeroberfläche verwenden möchten, die im Namespace System.Windows.Automation definiert sind. Aktuelle Informationen zur Automatisierung der Benutzeroberfläche finden Sie auf der Seite zur Windows-Automatisierungs-API: Benutzeroberflächenautomatisierung.

Dieser Artikel enthält Beispielcode, der zeigt, wie Sie ein Element in der Automatisierungsstruktur der Benutzeroberfläche anhand einer oder mehrerer bestimmter Eigenschaften finden.

Beispiel

Im folgenden Beispiel ist eine Reihe von Eigenschaftenbedingungen angegeben, die ein bestimmtes Element (oder mehrere Elemente) von Interesse in der AutomationElement-Struktur identifizieren. Dann wird eine Suche nach allen übereinstimmenden Elementen mithilfe der FindAll-Methode ausgeführt, die eine Reihe von Booleschen AndCondition-Operationen enthält, um die Anzahl der übereinstimmenden Elemente zu beschränken.

Hinweis

Beim Suchen vom RootElement sollten Sie versuchen, nur direkte untergeordnete Elemente zu erhalten. Eine Suche nach Nachfolgerelementen kann Hunderte oder sogar Tausende Elemente durchlaufen und möglicherweise einen Stapelüberlauf verursachen. Wenn Sie versuchen, ein bestimmtes Element auf einer niedrigeren Ebene abzurufen, sollten Sie die Suche aus dem Anwendungsfenster oder aus einem Container auf niedrigerer Ebene starten.

///--------------------------------------------------------------------
/// <summary>
/// Walks the UI Automation tree of the target and reports the control
/// type of each element it finds in the control view to the client.
/// </summary>
/// <param name="targetTreeViewElement">
/// The root of the search on this iteration.
/// </param>
/// <param name="elementIndex">
/// The TreeView index for this iteration.
/// </param>
/// <remarks>
/// This is a recursive function that maps out the structure of the
/// subtree of the target beginning at the AutomationElement passed in
/// as the rootElement on the first call. This could be, for example,
/// an application window.
/// CAUTION: Do not pass in AutomationElement.RootElement. Attempting
/// to map out the entire subtree of the desktop could take a very
/// long time and even lead to a stack overflow.
/// </remarks>
///--------------------------------------------------------------------
private void FindTreeViewDescendants(
    AutomationElement targetTreeViewElement, int treeviewIndex)
{
    if (targetTreeViewElement == null)
        return;

    AutomationElement elementNode =
        TreeWalker.ControlViewWalker.GetFirstChild(targetTreeViewElement);

    while (elementNode != null)
    {
        Label elementInfo = new Label();
        elementInfo.Margin = new Thickness(0);
        clientTreeViews[treeviewIndex].Children.Add(elementInfo);

        // Compile information about the control.
        elementInfoCompile = new StringBuilder();
        string controlName =
            (elementNode.Current.Name == "") ?
            "Unnamed control" : elementNode.Current.Name;
        string autoIdName =
            (elementNode.Current.AutomationId == "") ?
            "No AutomationID" : elementNode.Current.AutomationId;

        elementInfoCompile.Append(controlName)
            .Append(" (")
            .Append(elementNode.Current.ControlType.LocalizedControlType)
            .Append(" - ")
            .Append(autoIdName)
            .Append(")");

        // Test for the control patterns of interest for this sample.
        object objPattern;
        ExpandCollapsePattern expcolPattern;
        if (true == elementNode.TryGetCurrentPattern(ExpandCollapsePattern.Pattern, out objPattern))
        {
            expcolPattern = objPattern as ExpandCollapsePattern;
            if (expcolPattern.Current.ExpandCollapseState != ExpandCollapseState.LeafNode)
            {
                Button expcolButton = new Button();
                expcolButton.Margin = new Thickness(0, 0, 0, 5);
                expcolButton.Height = 20;
                expcolButton.Width = 100;
                expcolButton.Content = "ExpandCollapse";
                expcolButton.Tag = expcolPattern;
                expcolButton.Click +=
                    new RoutedEventHandler(ExpandCollapse_Click);
                clientTreeViews[treeviewIndex].Children.Add(expcolButton);
            }
        }
        TogglePattern togPattern;
        if (true == elementNode.TryGetCurrentPattern(TogglePattern.Pattern, out objPattern))
        {
            togPattern = objPattern as TogglePattern;
            Button togButton = new Button();
            togButton.Margin = new Thickness(0, 0, 0, 5);
            togButton.Height = 20;
            togButton.Width = 100;
            togButton.Content = "Toggle";
            togButton.Tag = togPattern;
            togButton.Click += new RoutedEventHandler(Toggle_Click);
            clientTreeViews[treeviewIndex].Children.Add(togButton);
        }
        InvokePattern invPattern;
        if (true == elementNode.TryGetCurrentPattern(InvokePattern.Pattern, out objPattern))
        {
            invPattern = objPattern as InvokePattern;
            Button invButton = new Button();
            invButton.Margin = new Thickness(0);
            invButton.Height = 20;
            invButton.Width = 100;
            invButton.Content = "Invoke";
            invButton.Tag = invPattern;
            invButton.Click += new RoutedEventHandler(Invoke_Click);
            clientTreeViews[treeviewIndex].Children.Add(invButton);
        }
        // Display compiled information about the control.
        elementInfo.Content = elementInfoCompile;
        Separator sep = new Separator();
        clientTreeViews[treeviewIndex].Children.Add(sep);

        // Iterate to next element.
        // elementNode - Current element.
        // treeviewIndex - Index of parent TreeView.
        FindTreeViewDescendants(elementNode, treeviewIndex);
        elementNode =
            TreeWalker.ControlViewWalker.GetNextSibling(elementNode);
    }
}
'''--------------------------------------------------------------------
''' <summary>
''' Walks the UI Automation tree of the target and reports the control 
''' type of each element it finds in the control view to the client.
''' </summary>
''' <param name="targetTreeViewElement">
''' The root of the search on this iteration.
''' </param>
''' <param name="treeviewIndex">
''' The TreeView index for this iteration.
''' </param>
''' <remarks>
''' This is a recursive function that maps out the structure of the 
''' subtree beginning at the AutomationElement passed in as 
''' rootElement on the first call. This could be, for example,
''' an application window.
''' CAUTION: Do not pass in AutomationElement.RootElement. Attempting 
''' to map out the entire subtree of the desktop could take a very 
''' long time and even lead to a stack overflow.
''' </remarks>
'''--------------------------------------------------------------------
Private Sub FindTreeViewDescendants( _
ByVal targetTreeViewElement As AutomationElement, _
ByVal treeviewIndex As Integer)
    If (IsNothing(targetTreeViewElement)) Then
        Return
    End If

    Dim elementNode As AutomationElement = _
    TreeWalker.ControlViewWalker.GetFirstChild(targetTreeViewElement)

    While Not (elementNode Is Nothing)
        Dim elementInfo As New Label()
        elementInfo.Margin = New Thickness(0)
        clientTreeViews(treeviewIndex).Children.Add(elementInfo)

        ' Compile information about the control.
        elementInfoCompile = New StringBuilder()
        Dim controlName As String
        If (elementNode.Current.Name = "") Then
            controlName = "Unnamed control"
        Else
            controlName = elementNode.Current.Name
        End If
        Dim autoIdName As String
        If (elementNode.Current.AutomationId = "") Then
            autoIdName = "No AutomationID"
        Else
            autoIdName = elementNode.Current.AutomationId
        End If


        elementInfoCompile.Append(controlName).Append(" (") _
        .Append(elementNode.Current.ControlType.LocalizedControlType) _
        .Append(" - ").Append(autoIdName).Append(")")

        ' Test for the control patterns of interest for this sample.
        Dim objPattern As Object = Nothing
        Dim expcolPattern As ExpandCollapsePattern
        If True = elementNode.TryGetCurrentPattern(ExpandCollapsePattern.Pattern, objPattern) Then
            expcolPattern = DirectCast(objPattern, ExpandCollapsePattern)
            If expcolPattern.Current.ExpandCollapseState <> ExpandCollapseState.LeafNode Then
                Dim expcolButton As New Button()
                expcolButton.Margin = New Thickness(0, 0, 0, 5)
                expcolButton.Height = 20
                expcolButton.Width = 100
                expcolButton.Content = "ExpandCollapse"
                expcolButton.Tag = expcolPattern
                AddHandler expcolButton.Click, AddressOf ExpandCollapse_Click
                clientTreeViews(treeviewIndex).Children.Add(expcolButton)
            End If
        End If
        Dim togPattern As TogglePattern
        If True = elementNode.TryGetCurrentPattern(TogglePattern.Pattern, objPattern) Then
            togPattern = DirectCast(objPattern, TogglePattern)
            Dim togButton As New Button()
            togButton.Margin = New Thickness(0, 0, 0, 5)
            togButton.Height = 20
            togButton.Width = 100
            togButton.Content = "Toggle"
            togButton.Tag = togPattern
            AddHandler togButton.Click, AddressOf Toggle_Click
            clientTreeViews(treeviewIndex).Children.Add(togButton)
        End If
        Dim invPattern As InvokePattern
        If True = elementNode.TryGetCurrentPattern(InvokePattern.Pattern, objPattern) Then
            invPattern = DirectCast(objPattern, InvokePattern)
            Dim invButton As New Button()
            invButton.Margin = New Thickness(0)
            invButton.Height = 20
            invButton.Width = 100
            invButton.Content = "Invoke"
            invButton.Tag = invPattern
            AddHandler invButton.Click, AddressOf Invoke_Click
            clientTreeViews(treeviewIndex).Children.Add(invButton)
        End If
        ' Display compiled information about the control.
        elementInfo.Content = elementInfoCompile
        Dim sep As New Separator()
        clientTreeViews(treeviewIndex).Children.Add(sep)

        ' Iterate to next element.
        ' elementNode - Current element.
        ' treeviewIndex - Index of parent TreeView.
        FindTreeViewDescendants(elementNode, treeviewIndex)
        elementNode = TreeWalker.ControlViewWalker.GetNextSibling(elementNode)
    End While

End Sub

Siehe auch