SelectionPattern.SelectionPatternInformation.IsSelectionRequired Eigenschaft

Definition

Namespace:

System.Windows.Automation

Assembly:

UIAutomationClient.dll

Ruft einen Wert ab, der angibt, ob der Container die Auswahl mindestens eines untergeordneten Elements erfordert.

public:
 property bool IsSelectionRequired { bool get(); };

public bool IsSelectionRequired { get; }

member this.IsSelectionRequired : bool

Public ReadOnly Property IsSelectionRequired As Boolean

Eigenschaftswert

Boolean

true, wenn das Steuerelement die Auswahl mindestens eines Elements erfordert, andernfalls false.

Beispiele

Im folgenden Beispiel wird ein SelectionPattern Steuerelementmuster aus einem AutomationElement abgerufen und anschließend zum Abrufen von Eigenschaftswerten verwendet.

///--------------------------------------------------------------------
/// <summary>
/// Obtains a SelectionPattern control pattern from an 
/// automation element.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <returns>
/// A SelectionPattern object.
/// </returns>
///--------------------------------------------------------------------
private SelectionPattern GetSelectionPattern(
    AutomationElement targetControl)
{
    SelectionPattern selectionPattern = null;

    try
    {
        selectionPattern =
            targetControl.GetCurrentPattern(SelectionPattern.Pattern)
            as SelectionPattern;
    }
    // Object doesn't support the SelectionPattern control pattern
    catch (InvalidOperationException)
    {
        return null;
    }

    return selectionPattern;
}

'''--------------------------------------------------------------------
''' <summary>
''' Obtains a SelectionPattern control pattern from an 
''' automation element.
''' </summary>
''' <param name="targetControl">
''' The automation element of interest.
''' </param>
''' <returns>
''' A SelectionPattern object.
''' </returns>
'''--------------------------------------------------------------------
Private Function GetSelectionPattern( _
ByVal targetControl As AutomationElement) As SelectionPattern
    Dim selectionPattern As SelectionPattern = Nothing

    Try
        selectionPattern = DirectCast( _
        targetControl.GetCurrentPattern(selectionPattern.Pattern), _
        SelectionPattern)
    ' Object doesn't support the SelectionPattern control pattern
    Catch
        Return Nothing
    End Try

    Return selectionPattern
End Function 'GetSelectionPattern

///--------------------------------------------------------------------
/// <summary>
/// Gets the current property values from target.
/// </summary>
/// <param name="selectionPattern">
/// A SelectionPattern control pattern obtained from 
/// an automation element representing the selection control.
/// </param>
/// <param name="automationProperty">
/// The automation property of interest.
/// </param>
///--------------------------------------------------------------------
private bool GetSelectionObjectProperty(
    SelectionPattern selectionPattern,
    AutomationProperty automationProperty)
{
    if (automationProperty.Id == 
        SelectionPattern.CanSelectMultipleProperty.Id)
    {
        return selectionPattern.Current.CanSelectMultiple;
    }
    if (automationProperty.Id == 
        SelectionPattern.IsSelectionRequiredProperty.Id)
    {
        return selectionPattern.Current.IsSelectionRequired;
    }
    return false;
}

'''--------------------------------------------------------------------
''' <summary>
''' Gets the current property values from target.
''' </summary>
''' <param name="selectionPattern">
''' A SelectionPattern control pattern obtained from 
''' an automation element representing the selection control.
''' </param>
''' <param name="automationProperty">
''' The automation property of interest.
''' </param>
'''--------------------------------------------------------------------
Private Function GetSelectionObjectProperty( _
ByVal selectionPattern As SelectionPattern, _
ByVal automationProperty As AutomationProperty) As Boolean
    If automationProperty.Id = _
    selectionPattern.CanSelectMultipleProperty.Id Then
        Return selectionPattern.Current.CanSelectMultiple
    End If
    If automationProperty.Id = _
    selectionPattern.IsSelectionRequiredProperty.Id Then
        Return selectionPattern.Current.IsSelectionRequired
    End If
    Return False
End Function 'GetSelectionObjectProperty

Hinweise

Diese Eigenschaft kann dynamisch sein. Im anfänglichen Zustand eines Steuerelements sind z. B. möglicherweise standardmäßig keine Elemente ausgewählt, wodurch angezeigt wird, dass IsSelectionRequiredfalseist. Nach dem Auswählen eines Elements muss für das Steuerelement jedoch immer mindestens ein Element ausgewählt sein.