CommandBinding.CanExecute Evento

public:
 event System::Windows::Input::CanExecuteRoutedEventHandler ^ CanExecute;

public event System.Windows.Input.CanExecuteRoutedEventHandler CanExecute;

member this.CanExecute : System.Windows.Input.CanExecuteRoutedEventHandler 

Public Custom Event CanExecute As CanExecuteRoutedEventHandler 

Public Event CanExecute As CanExecuteRoutedEventHandler 

Tipo de Evento

Exemplos

O exemplo seguinte cria um CommandBinding que mapeia um ExecutedRoutedEventHandler e um CanExecuteRoutedEventArgs handler para o Open comando.

<Window.CommandBindings>
  <CommandBinding Command="ApplicationCommands.Open"
                  Executed="OpenCmdExecuted"
                  CanExecute="OpenCmdCanExecute"/>
</Window.CommandBindings>

// Creating CommandBinding and attaching an Executed and CanExecute handler
CommandBinding OpenCmdBinding = new CommandBinding(
    ApplicationCommands.Open,
    OpenCmdExecuted,
    OpenCmdCanExecute);

this.CommandBindings.Add(OpenCmdBinding);

' Creating CommandBinding and attaching an Executed and CanExecute handler
Dim OpenCmdBinding As New CommandBinding(ApplicationCommands.Open, AddressOf OpenCmdExecuted, AddressOf OpenCmdCanExecute)

Me.CommandBindings.Add(OpenCmdBinding)

O que se segue mostra o CanExecuteRoutedEventHandler que define CanExecute para true.

void OpenCmdCanExecute(object sender, CanExecuteRoutedEventArgs e)
{
    e.CanExecute = true;
}

Private Sub OpenCmdCanExecute(ByVal sender As Object, ByVal e As CanExecuteRoutedEventArgs)
    e.CanExecute = True
End Sub

Observações

Quando o CanExecute método em a RoutedCommand é chamado, o PreviewCanExecute evento é ativado no alvo de comando. Se o evento não for tratado, o CanExecute evento é levantado. Se o alvo do comando tiver um CommandBinding para o comando, o CanExecute handler para esse CommandBinding é chamado. Se o destino do comando não tiver um CommandBinding para o comando, o CanExecute evento abre a árvore de elementos à procura de um elemento que tenha um CommandBinding associado ao comando.

Informação sobre Eventos Roteados

• O evento correspondente de tunelamento é PreviewCanExecute.

Ver também

• RoutedCommand
• InputBinding
• CommandManager