CacheRequest.TreeScope Özellik

Başvuru

Tanım

Ad Alanı:: System.Windows.Automation

Bütünleştirilmiş Kod:: UIAutomationClient.dll

Önemli

Bazı bilgiler ürünün ön sürümüyle ilgilidir ve sürüm öncesinde önemli değişiklikler yapılmış olabilir. Burada verilen bilgilerle ilgili olarak Microsoft açık veya zımni hiçbir garanti vermez.

Önbelleğe alma işleminin yalnızca alt ağacının kökü için mi yoksa alt ağaç veya alt öğeler için mi yapıldığını belirten bir değeri alır veya ayarlar.

public:
 property System::Windows::Automation::TreeScope TreeScope { System::Windows::Automation::TreeScope get(); void set(System::Windows::Automation::TreeScope value); };

public System.Windows.Automation.TreeScope TreeScope { get; set; }

member this.TreeScope : System.Windows.Automation.TreeScope with get, set

Public Property TreeScope As TreeScope

Özellik Değeri

TreeScope

Bir veya daha fazla Element, Children, Descendantsveya Subtree. Element varsayılan değerdir.

Özel durumlar

ArgumentException

özelliğini Parent veya Ancestorsolarak ayarlama girişiminde bulunuldu.

Örnekler

Aşağıdaki örnekte, bir etkin ve TreeScope olduğu Childrensırada üst pencere öğesinden bir CacheRequest liste kutusu öğesi elde edilir. Alt öğelerin (liste öğeleri) belirtilen özellikleri önbellekte depolanır ve liste kutusundan CachedChildren alınabilir.

/// <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

Açıklamalar

Önbelleğe alma kapsamı, getirilmekte olan nesne veya nesnelerle ilişkilidir, üzerinde çağrılan veya FindAll çağrılan FindFirst nesneyle ilişkili değildir. Örne bakın.

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