UserControl的ContextMenu中的RoutedCommand

Question

情況：

我有一個靜態的RoutedCommand定義如下：

public static class Commands
{
    public static readonly RoutedCommand GrowingOperation = new RoutedCommand("GrowingOperation", typeof(GrowingDisplay));
}

在MyUserControl.xaml我定義如下命令：

<UserControl.CommandBindings>
    <CommandBinding Command="{x:Static local:Commands.GrowingOperation}"
                    Executed="GrowingOperationExecuted"
                    CanExecute="GrowingOperationCanExecute"/>
</UserControl.CommandBindings>

然后在MyUserControl ContextMenu中像這樣使用它：

<UserControl.ContextMenu>
    <ContextMenu x:Name="GrowingContextMenu">
        <MenuItem Header="Grow"
                      Command="{x:Static local:Commands.GrowingOperation}"
                      CommandParameter="grow"/>
    </ContextMenu>
</UserControl.ContextMenu>

問題：

出現ContextMenu ，但不會GrowingOperationExecuted或GrowingOperationCanExecute 。 打開ContextMenu時也不會出現任何異常。

打開的ContextMenu如下所示：

它似乎已啟用，但是絕對沒有交互，甚至沒有懸停動畫。 錯誤在哪里？

編輯：

這里執行命令方法：

    private void GrowingOperationExecuted(object sender, ExecutedRoutedEventArgs e)
    {
        if (e.Parameter == null)
            throw new ArgumentException("ExecutedRoutedEventArgs must contain parameter.");
        var task = e.Parameter.ToString().ToLower();
        switch (task)
        {
            case "grow":
                Growing.SpeedUpGrowing();
                break;
            default:
                throw  new ArgumentOutOfRangeException();
        }
    }

    private void GrowingOperationCanExecute(object sender, CanExecuteRoutedEventArgs e)
    {
        if (e.Parameter == null)
            throw new ArgumentException("ExecutedRoutedEventArgs must contain parameter.");
        var task = e.Parameter.ToString().ToLower();
        switch (task)
        {
            case "grow":
                e.CanExecute = Growing.CanSpeedUpGrowing();
                break;
            default:
                throw new ArgumentOutOfRangeException();
        }
    }

編輯2：

MyUserControl的構造函數：

public GrowingDisplay()
    {
        InitializeComponent();

        HeightProperty.AddOwner(typeof (GrowingDisplay),
                                new FrameworkPropertyMetadata(OnHeightPropertyChanged));
        WidthProperty.AddOwner(typeof (GrowingDisplay),
                               new FrameworkPropertyMetadata(OnWidthPropertyChanged));

        CommandManager.InvalidateRequerySuggested();
    }

Answer 1

我將您的RoutedCommand的定義更改為：

private static RoutedUICommand _GrowingOperation;
public static RoutedCommand GrowingOperation
{
    get
    {
        if(_GrowingOperation == null)
        {
            _GrowingOperation = new RoutedUICommand("GrowingOperation", 
                                "GrowingOperation", typeof(WINDOWNAME));
        }
        return _GrowingOperation;
}

然后，可以通過將Commands類引入以下內容來清理XAML：

xmlns:commands="clr-namespace:NAMESPACE.Commands"

將其放在打開的窗口標簽中。 （假設這是一個窗口）然后在設置命令時可以使用：

<UserControl.CommandBindings>
<CommandBinding Command="commands:Commands.GrowingOperation"
                Executed="GrowingOperationExecuted"
                CanExecute="GrowingOperationCanExecute"/>

我唯一的問題是：您如何實現GrowingOperationExecuted和GrowingOperationCanExecute ？

Answer 2

這篇文章應該有助於解決您的問題： http : //wpftutorial.net/RoutedCommandsInContextMenu.html 。