TreeWalker(Condition) Constructor

Definitie

Naamruimte:
System.Windows.Automation
Assembly:
UIAutomationClient.dll

Initialiseert een nieuw exemplaar van de TreeWalker klasse.

public:
 TreeWalker(System::Windows::Automation::Condition ^ condition);
public TreeWalker(System.Windows.Automation.Condition condition);
new System.Windows.Automation.TreeWalker : System.Windows.Automation.Condition -> System.Windows.Automation.TreeWalker
Public Sub New (condition As Condition)

Parameters

condition
Condition

De weergave van de UI Automation elementstructuur die TreeWalker navigeert.

Voorbeelden

In het volgende voorbeeld ziet u hoe u een element TreeWalker kunt maken dat alleen tussen ingeschakelde elementen navigeert.

/// <summary>
/// Walks the UI Automation tree and adds the control type of each enabled control 
/// element it finds to a TreeView.
/// </summary>
/// <param name="rootElement">The root of the search on this iteration.</param>
/// <param name="treeNode">The node in the TreeView for this iteration.</param>
/// <remarks>
/// This is a recursive function that maps out the structure of the subtree beginning at the
/// UI Automation element 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 void WalkEnabledElements(AutomationElement rootElement, TreeNode treeNode)
{
    Condition condition1 = new PropertyCondition(AutomationElement.IsControlElementProperty, true);
    Condition condition2 = new PropertyCondition(AutomationElement.IsEnabledProperty, true);
    TreeWalker walker = new TreeWalker(new AndCondition(condition1, condition2));
    AutomationElement elementNode = walker.GetFirstChild(rootElement);
    while (elementNode != null)
    {
        TreeNode childTreeNode = treeNode.Nodes.Add(elementNode.Current.ControlType.LocalizedControlType);
        WalkEnabledElements(elementNode, childTreeNode);
        elementNode = walker.GetNextSibling(elementNode);
    }
}

''' <summary>
''' Walks the UI Automation tree and adds the control type of each enabled control 
''' element it finds to a TreeView.
''' </summary>
''' <param name="rootElement">The root of the search on this iteration.</param>
''' <param name="treeNode">The node in the TreeView for this iteration.</param>
''' <remarks>
''' This is a recursive function that maps out the structure of the subtree beginning at the
''' UI Automation element 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 WalkEnabledElements(ByVal rootElement As AutomationElement, ByVal treeNode As TreeNode)
    Dim condition1 As New PropertyCondition(AutomationElement.IsControlElementProperty, True)
    Dim condition2 As New PropertyCondition(AutomationElement.IsEnabledProperty, True)
    Dim walker As New TreeWalker(New AndCondition(condition1, condition2))
    Dim elementNode As AutomationElement = walker.GetFirstChild(rootElement)
    While (elementNode IsNot Nothing)
        Dim childTreeNode As TreeNode = treeNode.Nodes.Add(elementNode.Current.ControlType.LocalizedControlType)
        WalkEnabledElements(elementNode, childTreeNode)
        elementNode = walker.GetNextSibling(elementNode)
    End While

End Sub

Opmerkingen

UI Automation elementen die niet overeenkomen met condition worden overgeslagen wanneer TreeWalker wordt gebruikt om door de elementstructuur te navigeren.

Als uw clienttoepassing mogelijk elementen in een eigen gebruikersinterface probeert te vinden, moet u alle UI Automation aanroepen uitvoeren op een afzonderlijke thread.

Van toepassing op

Zie ook