SelectionPattern.SelectionPatternInformation.IsSelectionRequired Propriedade

Definição

Obtém um valor que especifica se o contêiner exige que pelo menos um item filho seja selecionado.Gets a value that specifies whether the container requires at least one child item to be selected.

public:
 property bool IsSelectionRequired { bool get(); };
public bool IsSelectionRequired { get; }
member this.IsSelectionRequired : bool
Public ReadOnly Property IsSelectionRequired As Boolean

Valor da propriedade

trueSe o controle exigir que pelo menos um item seja selecionado; caso falsecontrário.true if the control requires at least one item to be selected; otherwise false.

Exemplos

No exemplo a seguir, um SelectionPattern padrão de controle é obtido de AutomationElement um e, posteriormente, usado para recuperar valores de propriedade.In the following example, a SelectionPattern control pattern is obtained from an AutomationElement and subsequently used to retrieve property values.

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

Comentários

Essa propriedade pode ser dinâmica.This property can be dynamic. Por exemplo, o estado inicial de um controle pode não ter nenhum item selecionado por padrão, indicando que IsSelectionRequired é false.For example, the initial state of a control might not have any items selected by default, indicating that IsSelectionRequired is false. No entanto, depois que um item é selecionado, o controle sempre deve ter pelo menos um item selecionado.However, after an item is selected, the control must always have at least one item selected.

Aplica-se a