C#设计模式- 观察者模式（2）

using System;using System.Collections.Generic;using System.Text;namespace 观察者模式{    class Program    {        static void Main(string[] args)        {            //前台小姐童子喆            Secretary tongzizhe = new Secretary();            //看股票的同事            StockObserver tongshi1 = new StockObserver("魏关姹", tongzizhe);            StockObserver tongshi2 = new StockObserver("易管查", tongzizhe);            //前台记下了两位同事            tongzizhe.Attach(tongshi1);            tongzizhe.Attach(tongshi2);            //发现老板回来            tongzizhe.SecretaryAction = "老板回来了！";            //通知两个同事            tongzizhe.Notify();            Console.Read();        }    }    //前台秘书类    class Secretary    {        //同事列表        private IList<StockObserver> observers = new List<StockObserver>();        private string action;        //增加        public void Attach(StockObserver observer)        {            observers.Add(observer);        }        //减少        public void Detach(StockObserver observer)        {            observers.Remove(observer);        }        //通知        public void Notify()        {            foreach (StockObserver o in observers)                o.Update();        }        //前台状态        public string SecretaryAction        {            get { return action; }            set { action = value; }        }    }    //看股票的同事    class StockObserver    {        private string name;        private Secretary sub;        public StockObserver(string name, Secretary sub)        {            this.name = name;            this.sub = sub;        }        public void Update()        {            Console.WriteLine("{0} {1} 关闭股票行情，继续工作！", sub.SecretaryAction, name);        }    }}