Observer

using System;
using System.Collections.Generic;
using System.Text;

namespace Design_Pattern.Observer
{
    public delegate void SubEventHandler();

    public abstract class Subject
    {
        public event SubEventHandler subEvent;

        protected void OnFireWay()
        {
            if (this.subEvent != null)
            {
                subEvent();
            }
        }

        public abstract void Cry();
    }

        public class Cat:Subject
        {
            public override void Cry()
            {
                this.OnFireWay();
            }
        }

        public abstract class Observer
        {
            public Observer(Subject sub)
            {
                sub.subEvent += new SubEventHandler(Response);
            }

            public abstract void Response();
        }

        public class Mouse:Observer
        {
            private string name;
            public override void Response()
            {
                Console.WriteLine(this.name+"   Wa!!Run");
            }

            public Mouse(string name, Subject sub):base(sub)
            {
                this.name = name;
            }
        }

        public class Test2
        {
           public static void Main()
            {
                Console.WriteLine("HEllO");
                Subject sub = new Cat();
                Console.WriteLine("1");
                Observer mouse1 = new Mouse("mouse1", sub);
                Observer mouse2 = new Mouse("mouse2", sub);
                sub.Cry();
                Console.ReadLine();
            }
        }
}

/**//*
 * 类应该依赖于抽象 而不应该依赖于具体类 依赖倒置原则
 * 面向接口编程 接口稳定 表达了契约的合同
 * 单一职责原则
 * 开闭原则
 */
using System;
using System.Collections.Generic;
using System.Text;

namespace DesignPattern.Observer2
{
   // public delegate void AccountChangedEventhandler(Object sender, EventArgs args);
   public delegate void AccountChangedEventhandler();

    class BankAccount 
    {
        public event AccountChangedEventhandler AccountChanged;

        private void OnAccountChanged()
        {
            if (AccountChanged != null)
            {
                AccountChanged();
            }
        }

        public new void WithDraw()
        {
            //.
            this.OnAccountChanged();
        }
    }

    interface IObserver
    {
        void Send();
    }

    class Mailer : IObserver
    {
        public void Send()
        {
            Console.WriteLine("Send email message");
        }

    }

    class Mobile : IObserver
    {
        public void Send()
        {
            Console.WriteLine("Send Mobile message");
        }
    }

    class App
    {
        //public static void Main()
        //{
        //    BankAccount account = new BankAccount();
        //    //Mobile mobile = new Mobile();

        //    account.AccountChanged += new AccountChangedEventhandler(new Mobile().Send);
        //    account.AccountChanged += new AccountChangedEventhandler(new Mailer().Send);

        //    account.WithDraw();

        //    Console.ReadLine();
        //}
    }
}