wpf mvvm MenuItem的Command事件

这是一个事件的辅助类，可以通过它实现MenuItem的Command事件

public class MyCommands : Freezable, ICommand, ICommandSource
    {

        public MyCommands() 
        {
        }

        public static readonly DependencyProperty CommandParameterProperty =
          DependencyProperty.Register(
              "CommandParameter",
              typeof(object),
              typeof(MyCommands),
              new PropertyMetadata((object)null));

        public object CommandParameter
        {
            get
            {
                return (object)GetValue(CommandPa