Question

代码：

public partial class MainWindow : Window
{
    public static readonly RoutedCommand TestRoutedCommand = new RoutedCommand();

    public MainWindow()
    {
        InitializeComponent();


        CommandBinding testCommandBinding = new CommandBinding(TestRoutedCommand, Test_Executed, Test_CanExecute);
        testCommandBinding.PreviewExecuted += Test_PreviewExecuted;

        buttonTest.CommandBindings.Add(testCommandBinding);

        // WHEN I UNCOMMENT THAT LINE, ONLY THE "Preview" MESSAGEBOX IS SHOWN
        //TestRoutedCommand.Execute(null, buttonTest);    
        // Ok, I understood that part here: http://stackoverflow.com/a/4877259/48729
    }

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

    private void Test_PreviewExecuted(object sender, ExecutedRoutedEventArgs e)
    {
        MessageBox.Show("Preview");
    }

    private void Test_Executed(object sender, ExecutedRoutedEventArgs e)
    {
        MessageBox.Show("Executed");
    }
}

XAML，它是一个测试表单，所以只有那个按钮：

<Button x:Name="buttonTest" Width="30" Height="30">Test</Button>

当我点击＆＃34;测试＆＃34;按钮，没有任何反应，没有CanExecute，没有PreviewExecuted，没有执行...

该代码有什么问题？

Answer 1

在您的代码中创建CommandBinding，它说明如何处理特定命令（TestRoutedCommand），但是您不执行此命令（除非您取消注释您的行）。如果要在按钮单击时执行它，只需执行：

buttonTest.Command = TestRoutedCommand;

为什么RoutedCommand不能使用该代码？

1 个答案: