CommandManager.AddPreviewExecutedHandler Méthode

Définition

Espace de noms:

System.Windows.Input

Assembly:

PresentationCore.dll

Attache le ExecutedRoutedEventHandler spécifié à l'élément spécifié.

public:
 static void AddPreviewExecutedHandler(System::Windows::UIElement ^ element, System::Windows::Input::ExecutedRoutedEventHandler ^ handler);

public static void AddPreviewExecutedHandler (System.Windows.UIElement element, System.Windows.Input.ExecutedRoutedEventHandler handler);

static member AddPreviewExecutedHandler : System.Windows.UIElement * System.Windows.Input.ExecutedRoutedEventHandler -> unit

Public Shared Sub AddPreviewExecutedHandler (element As UIElement, handler As ExecutedRoutedEventHandler)

Paramètres

element

UIElement

Élément auquel attacher handler.

handler

ExecutedRoutedEventHandler

Gestionnaire de l'événement CanExecute.

Exceptions

ArgumentNullException

element ou handler est null.

Exemples

L’exemple suivant crée un CanExecuteRoutedEventHandler et un ExecutedRoutedEventHandler et les attache à un Button qui est une source de commande pour la Help commande.

Tout d’abord, le Button est créé et associé à la Help commande.

<Button Command="ApplicationCommands.Help"
        Name="helpButton">Help</Button>

CanExecuteRoutedEventHandler et ExecutedRoutedEventHandler sont ensuite créés.

private void HelpCmdExecuted(object sender, ExecutedRoutedEventArgs e)
{
    // OpenHelpFile opens the help file
    OpenHelpFile();
}

Private Sub HelpCmdExecuted(ByVal sender As Object, ByVal e As ExecutedRoutedEventArgs)
    ' OpenHelpFile opens the help file
    OpenHelpFile()
End Sub

private void HelpCmdCanExecute(object sender, CanExecuteRoutedEventArgs e)
{
    // HelpFilesExists() determines if the help file exists
    if (HelpFileExists() == true)
    {
        e.CanExecute = true;
    }
    else
    {
        e.CanExecute = false;
    }
}

Private Sub HelpCmdCanExecute(ByVal sender As Object, ByVal e As CanExecuteRoutedEventArgs)
    ' HelpFilesExists() determines if the help file exists
    If HelpFileExists() = True Then
        e.CanExecute = True
    Else
        e.CanExecute = False
    End If
End Sub

Enfin, les gestionnaires sont attachés à l’à l’aide de Button et AddCanExecuteHandlerAddExecutedHandler.

CommandManager.AddExecutedHandler(helpButton, HelpCmdExecuted);
CommandManager.AddCanExecuteHandler(helpButton, HelpCmdCanExecute);

CommandManager.AddExecutedHandler(helpButton, AddressOf HelpCmdExecuted)
CommandManager.AddCanExecuteHandler(helpButton, AddressOf HelpCmdCanExecute)

Voir aussi

• RoutedCommand
• ICommand