Dunk

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

namespace DesignModelTest.觀察者
{

    /// <summary>
    /// 被觀察者
    /// </summary>
    abstract class Subject
    {
        //要通知的觀察者
        private List<Observer> observers = new List<Observer>();
        /// <summary>
        /// 加入觀察者.
        /// </summary>
        /// <param name="observer">The observer.</param>
        public void Attach(Observer observer)
        {
            observers.Add(observer);
        }
        /// <summary>
        /// 移除觀察者.
        /// </summary>
        /// <param name="observer">The observer.</param>
        public void Detach(Observer observer)
        {
            observers.Remove(observer);
        }
        /// <summary>
        /// 發出訊息通知觀察者做下一步動作.
        /// </summary>
        public void Notify()
        {
            foreach (Observer tmpobserver in observers)
            {
                tmpobserver.OpenDoor();
            }
        }
    }
    /// <summary>
    /// 觀察者介面
    /// </summary>
    abstract class Observer
    {
       public abstract void OpenDoor();
    }
    /// <summary>
    /// 被觀察的對象:老闆
    /// </summary>
    class Boss : Subject
    {
        private string _subjectState;
        public string subjectState
        {
            get { return _subjectState; }
            set { _subjectState = value; }
        }
        private string _name;
        public string name
        {
            get { return _name;}
            set { _name = value;}
        }
    }
    /// <summary>
    /// 觀察者:員工
    /// </summary>
    class Employee : Observer
    {
        private string name;
        private Boss boss;
        public Employee(Boss iniboss, string inputname)
        {
            boss = iniboss;
            name = inputname;
        }
        public override void OpenDoor()
        {
            Console.WriteLine("員工{0}幫老闆{1}開門,老闆覺得{2}", name, boss.name, boss.subjectState);
        }
    }
    /// <summary>
    /// 觀察者:司機
    /// </summary>
    class Driver : Observer
    {
        private string name;
        private Boss boss;
        public Driver(Boss iniboss, string inputname)
        {
            boss = iniboss;
            name = inputname;
        }
        public override void OpenDoor()
        {
            Console.WriteLine("司機{0}幫老闆{1}開門,老闆覺得{2}", name, boss.name, boss.subjectState);
        }
    }

}

            //被觀察者:老闆
            DesignModelTest.觀察者.Boss boss = new DesignModelTest.觀察者.Boss();
            boss.name = "阿狗";
            boss.subjectState = "很屌";
            //觀察者:員工小張
            DesignModelTest.觀察者.Observer chang = new DesignModelTest.觀察者.Employee(boss, "小張");
            //增加觀察者
            boss.Attach(chang);
            //發出訊息
            boss.Notify();
            //移除觀察者
            boss.Detach(chang);
            boss.name = "阿貓";
            boss.subjectState = "很差";
            DesignModelTest.觀察者.Observer liao = new DesignModelTest.觀察者.Driver(boss, "小廖");
            boss.Attach(liao);
            boss.Notify();
            Console.Read();
            #endregion