SelectionPattern.SelectionPatternInformation.IsSelectionRequired Proprietà

Definizione

Spazio dei nomi:

System.Windows.Automation

Assembly:

UIAutomationClient.dll

Ottiene un valore che specifica se il contenitore richiede la selezione di almeno un elemento figlio.

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

public bool IsSelectionRequired { get; }

member this.IsSelectionRequired : bool

Public ReadOnly Property IsSelectionRequired As Boolean

Valore della proprietà

Boolean

true se il controllo richiede la selezione di almeno un elemento figlio. In caso contrario, false.

Esempio

Nell'esempio seguente viene ottenuto un SelectionPattern pattern di controllo da un AutomationElement oggetto e successivamente usato per recuperare i valori delle proprietà.

///--------------------------------------------------------------------
/// <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

Commenti

Questa proprietà può essere dinamica. Ad esempio, lo stato iniziale di un controllo potrebbe prevedere la selezione di nessun elemento per impostazione predefinita, a indicare che IsSelectionRequired è false. Tuttavia, dopo aver selezionato un elemento, il controllo deve sempre avere almeno un elemento selezionato.