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TreeWalker(Condition) Constructeur

Définition

Initialise une nouvelle instance de la classe TreeWalker.

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)

Paramètres

condition
Condition

Vue de l’arborescence d’éléments UI Automation qui TreeWalker naviguera.

Exemples

L’exemple suivant montre comment construire un TreeWalker élément qui navigue uniquement entre les éléments activés.

/// <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

Remarques

UI Automation éléments qui ne correspondent condition pas sont ignorés lorsqu’ils TreeWalker sont utilisés pour naviguer dans l’arborescence d’éléments.

Si votre application cliente peut essayer de trouver des éléments dans sa propre interface utilisateur, vous devez effectuer tous les appels UI Automation sur un thread distinct.

S’applique à

Voir aussi