在WPF中,如何实现ICommandSource以使我的自定义控制能力能够使用来自xaml的命令？

Question

您能否提供一个示例,了解如何实现ICommandSource界面.因为我希望我的UserControl,没有能力在xaml中指定命令,才能拥有此功能.并且能够在用户点击时处理该命令CustomControl.

Answer 1

这是一个例子:

public partial class MyUserControl : UserControl, ICommandSource
{
    public MyUserControl()
    {
        InitializeComponent();
    }



    public ICommand Command
    {
        get { return (ICommand)GetValue(CommandProperty); }
        set { SetValue(CommandProperty, value); }
    }

    public static readonly DependencyProperty CommandProperty =
        DependencyProperty.Register("Command", typeof(ICommand), typeof(MyUserControl), new UIPropertyMetadata(null));


    public object CommandParameter
    {
        get { return (object)GetValue(CommandParameterProperty); }
        set { SetValue(CommandParameterProperty, value); }
    }

    // Using a DependencyProperty as the backing store for CommandParameter.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty CommandParameterProperty =
        DependencyProperty.Register("CommandParameter", typeof(object), typeof(MyUserControl), new UIPropertyMetadata(null));

    public IInputElement CommandTarget
    {
        get { return (IInputElement)GetValue(CommandTargetProperty); }
        set { SetValue(CommandTargetProperty, value); }
    }

    // Using a DependencyProperty as the backing store for CommandTarget.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty CommandTargetProperty =
        DependencyProperty.Register("CommandTarget", typeof(IInputElement), typeof(MyUserControl), new UIPropertyMetadata(null));


    protected override void OnMouseLeftButtonUp(MouseButtonEventArgs e)
    {
        base.OnMouseLeftButtonUp(e);

        var command = Command;
        var parameter = CommandParameter;
        var target = CommandTarget;

        var routedCmd = command as RoutedCommand;
        if (routedCmd != null && routedCmd.CanExecute(parameter, target))
        {
            routedCmd.Execute(parameter, target);
        }
        else if (command != null && command.CanExecute(parameter))
        {
            command.Execute(parameter);
        }
    }

}

请注意,该CommandTarget属性仅用于RoutedCommands