CommandManager.AddExecutedHandler 方法
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
將指定 ExecutedRoutedEventHandler 元素附加到指定元素上。
public:
static void AddExecutedHandler(System::Windows::UIElement ^ element, System::Windows::Input::ExecutedRoutedEventHandler ^ handler);
public static void AddExecutedHandler(System.Windows.UIElement element, System.Windows.Input.ExecutedRoutedEventHandler handler);
static member AddExecutedHandler : System.Windows.UIElement * System.Windows.Input.ExecutedRoutedEventHandler -> unit
Public Shared Sub AddExecutedHandler (element As UIElement, handler As ExecutedRoutedEventHandler)
參數
- element
- UIElement
該 handler 依靠的元素。
- handler
- ExecutedRoutedEventHandler
被處決的操控者。
例外狀況
element 或 handler 為 null。
範例
以下範例會產生 a CanExecuteRoutedEventHandler 和 an ExecutedRoutedEventHandler ,並將其附加到 a,a Button 是該指令的指令來源 Help 。
<Button Command="ApplicationCommands.Help"
Name="helpButton">Help</Button>
接著,創造 和 CanExecuteRoutedEventHandler 。ExecutedRoutedEventHandler
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())
{
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
最後,處理器會連接到 Button ,使用 和 AddCanExecuteHandlerAddExecutedHandler。
CommandManager.AddExecutedHandler(helpButton, HelpCmdExecuted);
CommandManager.AddCanExecuteHandler(helpButton, HelpCmdCanExecute);
CommandManager.AddExecutedHandler(helpButton, AddressOf HelpCmdExecuted)
CommandManager.AddCanExecuteHandler(helpButton, AddressOf HelpCmdCanExecute)