AutomationElement.CachedParent Eigenschap

public:
 property System::Windows::Automation::AutomationElement ^ CachedParent { System::Windows::Automation::AutomationElement ^ get(); };

public System.Windows.Automation.AutomationElement CachedParent { get; }

member this.CachedParent : System.Windows.Automation.AutomationElement

Public ReadOnly Property CachedParent As AutomationElement

Waarde van eigenschap

Het bovenliggende element. De retourwaarde kan zijn null als het opgegeven element geen bovenliggend element heeft, bijvoorbeeld als dit element het hoofdknooppunt is.

Uitzonderingen

Voorbeelden

In het volgende voorbeeld worden de eigenschappen van een keuzelijst en de bijbehorende lijstitems in de Name cache opgeslagen. Het keuzelijstelement is beschikbaar in de CachedParent eigenschap van elk element van het lijstitem.

/// <summary>
/// Gets a list box element and caches the Name property of its children (the list items).
/// </summary>
/// <param name="elementMain">The UI Automation element for the parent window.</param>
void CachePropertiesWithScope(AutomationElement elementMain)
{
    AutomationElement elementList;

    // Set up the CacheRequest.
    CacheRequest cacheRequest = new CacheRequest();
    cacheRequest.Add(AutomationElement.NameProperty);
    cacheRequest.TreeScope = TreeScope.Element | TreeScope.Children;

    // Activate the CacheRequest and get the element. Note that the scope of the CacheRequest
    // is in relation to the object being retrieved: the list box and its children are 
    // cached, not the main window and its children.
    using (cacheRequest.Activate())
    {
        // Load the list element and cache the specified properties for its descendants.
        Condition cond = new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.List);
        elementList = elementMain.FindFirst(TreeScope.Children, cond);
    }
    if (elementList == null) return;

    // The following illustrates that the children of the list are in the cache.
    foreach (AutomationElement listItem in elementList.CachedChildren)
    {
        Console.WriteLine(listItem.Cached.Name);
    }

    // The following call raises an exception, because the IsEnabled property was not cached.
    /*** Console.WriteLine(listItem.Cached.IsEnabled); ***/

    // The following illustrates that because the list box itself was cached, it is now
    // available as the CachedParent of each list item.
    AutomationElement child = elementList.CachedChildren[0];
    Console.WriteLine(child.CachedParent.Cached.Name);
}

''' <summary>
''' Gets a list box element and caches the Name property of its children (the list items).
''' </summary>
''' <param name="elementMain">The UI Automation element for the parent window.</param>
Sub CachePropertiesWithScope(ByVal elementMain As AutomationElement)
    Dim elementList As AutomationElement

    ' Set up the CacheRequest.
    Dim cacheRequest As New CacheRequest()
    cacheRequest.Add(AutomationElement.NameProperty)
    cacheRequest.TreeScope = TreeScope.Element Or TreeScope.Children

    ' Activate the CacheRequest and get the element. Note that the scope of the CacheRequest
    ' is in relation to the object being retrieved: the list box and its children are 
    ' cached, not the main window and its children.
    Using cacheRequest.Activate()
        ' Load the list element and cache the specified properties for its descendants.
        Dim myCondition As New PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.List)
        elementList = elementMain.FindFirst(TreeScope.Children, myCondition)

        If elementList Is Nothing Then
            Return
        End If

        ' The following illustrates that the children of the list are in the cache.
        Dim listItem As AutomationElement
        For Each listItem In elementList.CachedChildren
            Console.WriteLine(listItem.Cached.Name)
        Next listItem

        ' The following call raises an exception, because the IsEnabled property was not cached.
        '** Console.WriteLine(listItem.Cached.IsEnabled) **

        ' The following illustrates that because the list box itself was cached, it is now
        ' available as the CachedParent of each list item.
        Dim child As AutomationElement = elementList.CachedChildren(0)
        Console.WriteLine(child.CachedParent.Cached.Name)
    End Using
End Sub

Zie ook

• Caching in UI Automation Clients