事件和行动代表之间有什么区别

Question

我正在学习事件，并发现使用Action代理也可以实现类似的功能。使用Action委托，它不是发布订阅模型，但它允许客户端传入类似于事件的方法引用，实际类可以在需要时调用它。

 class Program
    {
        static void Main(string[] args)
        {
            Subscriber s = new Subscriber();
            NewSubscriber n = new NewSubscriber();

        }
    }

    class TimeTick : EventArgs
    {
        public DateTime Current { get; set; }
        public TimeTick()
        {

        }
    }
    /**Publisher suscriber model using events**/
    delegate void MyDelegate(object o, TimeTick e);
    class Publisher
    {
        public event MyDelegate MyEvent;
        public Publisher()
        {

        }
        public void Start()
        {
            while (1 == 1)
            {
                Thread.Sleep(5000);
                if (MyEvent != null)
                {
                    MyEvent(this, new TimeTick() { Current = DateTime.Now });
                }
            }
        }
    }
    class Subscriber
    {
        public Subscriber()
        {
            Publisher p = new Publisher();
            p.MyEvent += P_MyEvent;
            p.Start();
        }

        private void P_MyEvent(object o, TimeTick e)
        {
            Console.WriteLine(e.Current);
        }
    }

    /**Publisher suscriber model using Action delegates**/
    class NewPublisher
    {
        public NewPublisher()
        {

        }
        public void Start(Action<TimeTick> MyAction)
        {
            while (1 == 1)
            {
                Thread.Sleep(5000);
                if (MyAction != null)
                {
                    MyAction.Invoke(new TimeTick() { Current = DateTime.Now });
                }
            }
        }
    }
    class NewSubscriber
    {
        public NewSubscriber()
        {
            NewPublisher p = new NewPublisher();
            p.Start(new Action<TimeTick>(P_MyEvent));
        }

        public void P_MyEvent(TimeTick e)
        {
            Console.WriteLine(e.Current);
        }
    }