委托与事件

1.直接使用delegate

不废话，直接上代码

namespace DelegateEventTest
{
    class Program
    {
        static void Main(string[] args)
        {
            //模拟场景，主人通知宠物们来吃饭了，宠物们收到消息

            Master m1 = new Master();

            // 多播委托
            m1.NofifyDelegateHandler += (new Cat()).Receive;
            m1.NofifyDelegateHandler += (new Dog()).Receive;

            m1.notify("吃饭了");
        }
    }
    /// <summary>
    /// 主人类
    /// </summary>
    public class Master
    {
        // 委托 
        public delegate void NotifyDelegate(string message);

        // 事件：可以理解是带event关键字的委托的实例
        public event NotifyDelegate NofifyDelegateHandler;
        // 一个普通方法，当实例调用改方法时, 会去调用事件
        public void notify(string message)
        {
            Console.WriteLine($"我是{this.GetType().Name}, 通知:{message}");
            if (this.NofifyDelegateHandler != null)
            {
                this.NofifyDelegateHandler(message);
            }
        }
    }
    // 定义一个接受消息的接口
    public interface IReceiveMessage
    {
        void Receive(string message);
    }
    // 猫咪类
    public class Cat : IReceiveMessage
    {
        public void Receive(string message)
        {
            Console.WriteLine($"我是{this.GetType().Name},收到信息：{message}, 喵喵喵");
        }

    }
    // 狗狗类
    public class Dog : IReceiveMessage
    {
        public void Receive(string message)
        {
            Console.WriteLine($"我是{this.GetType().Name},收到信息：{message}, 汪汪汪");
        }

    }
}

运行结果

image.png

2.使用Action

namespace DelegateEventTest
{
    class Program
    {
        static void Main(string[] args)
        {
            //模拟场景，主人通知宠物们来吃饭了，宠物们收到消息

            Master m1 = new Master();

            m1.NotifyAction += ((new Cat()).Receive);
            m1.NotifyAction += (new Dog()).Receive;

            m1.notify2("吃饭了");
        }
    }
    /// <summary>
    /// 主人类
    /// </summary>
    public class Master
    {
        public event Action<string> NotifyAction;

        public void notify2(string message)
        {
            Console.WriteLine($"我是{this.GetType().Name}, 通知:{message}");
            NotifyAction(message);
        }
    }
    // 定义一个接受消息的接口
    public interface IReceiveMessage
    {
        void Receive(string message);
    }
    // 猫咪类
    public class Cat : IReceiveMessage
    {
        public void Receive(string message)
        {
            Console.WriteLine($"我是{this.GetType().Name},收到信息：{message}, 喵喵喵");
        }

    }
    // 狗狗类
    public class Dog : IReceiveMessage
    {
        public void Receive(string message)
        {
            Console.WriteLine($"我是{this.GetType().Name},收到信息：{message}, 汪汪汪");
        }

    }
}

结果一样

image.png