CommandBinding.CanExecute 事件

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 

事件類型

範例

下列範例會CommandBinding建立 ，將 和 CanExecuteRoutedEventArgs 處理程式對應ExecutedRoutedEventHandler至 Open 命令。

<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)

以下顯示設定為 true的 CanExecuteRoutedEventHandlerCanExecute 。

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

備註

CanExecute呼叫 上的 RoutedCommand 方法時，PreviewCanExecute會在命令目標上引發 事件。 如果未處理事件，則會 CanExecute 引發 事件。 如果命令目標具有 CommandBinding 命令的 ，則會 CanExecute 呼叫的 CommandBinding 處理程式。 如果命令目標沒有 CommandBinding 命令的 ，則 CanExecute 事件會將專案樹狀結構反升，搜尋與 CommandBinding 命令相關聯的專案。

路由事件資訊

• 對應的通道事件為 PreviewCanExecute。

適用於

另請參閱

• RoutedCommand
• InputBinding
• CommandManager