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AutomationElement.Cached Propriedade

  • Referência

Definição

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

Obtém os valores de propriedade Automação da Interface do Usuário armazenados em cache para esse AutomationElement objeto.

public:
 property System::Windows::Automation::AutomationElement::AutomationElementInformation Cached { System::Windows::Automation::AutomationElement::AutomationElementInformation get(); };
public System.Windows.Automation.AutomationElement.AutomationElementInformation Cached { get; }
member this.Cached : System.Windows.Automation.AutomationElement.AutomationElementInformation
Public ReadOnly Property Cached As AutomationElement.AutomationElementInformation

Valor da propriedade

AutomationElement.AutomationElementInformation

Uma estrutura que contém os valores da propriedade armazenada em cache para o AutomationElement.

Exceções

InvalidOperationException

Não existem propriedades armazenadas em cache.

ElementNotAvailableException

A interface do usuário do AutomationElement não existe mais.

Exemplos

O exemplo a seguir mostra como a Name propriedade pode ser armazenada em cache e, em seguida, recuperada usando a Cached propriedade.

/// <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

Comentários

Os acessadores para propriedades Automação da Interface do Usuário são representados como propriedades da estrutura retornada por Cached. Você não precisa recuperar a estrutura; você pode acessar seus membros diretamente, como no exemplo abaixo. Para obter informações específicas sobre as propriedades disponíveis e seu uso, consulte AutomationElement.AutomationElementInformation.

Para obter o valor atual das propriedades Automação da Interface do Usuário nesse elemento, use a Current propriedade.

Aplica-se a

Confira também