观察者设计模式 - 猫和老鼠

问题:猫一叫喊 所有的老鼠都逃跑

要点：1. 联动效果，运行代码只要执行Cat.Cryed()方法。2. 对老鼠和主人进行抽象 
评分标准: <1>.构造出Cat、Mouse、Master三个类，并能使程序运行(2分) 
            <2>从Mouse和Master中提取抽象（5分） 
            <3>联动效应，只要执行Cat.Cryed()就可以使老鼠逃跑，主人惊醒。(3分) 


    public interface Observer 
    { 
        void Response();    //观察者的响应，如是老鼠见到猫的反映 
    } 
    public interface Subject 
    { 
        void AimAt(Observer obs);  //针对哪些观察者，这里指猫的要扑捉的对象---老鼠 
    } 
    public class Mouse : Observer 
    { 
        private string name; 
        public Mouse(string name, Subject subj) 
        {           
            this.name = name; 
            subj.AimAt(this); 
        } 
        
        public void Response() 
        { 
            Console.WriteLine(name + " attempt to escape!"); 
        } 
    } 
    public class Master : Observer 
    {   
        public Master(Subject subj) 
        {           
            subj.AimAt(this); 
        } 
        
        public void Response() 
        { 
            Console.WriteLine("Host waken!"); 
        }  
    } 
  
    public class Cat : Subject 
    { 
        private ArrayList observers; 
        public Cat() 
        {   
            this.observers = new ArrayList(); 
        } 
        public void AimAt(Observer obs) 
        { 
            this.observers.Add(obs); 
        } 
        public void Cry() 
        { 
            Console.WriteLine("Cat cryed!"); 
            foreach (Observer obs in this.observers) 
            { 
                obs.Response(); 
            } 
        } 
    } 
    class MainClass 
    {       
        static void Main(string[] args) 
        { 
            Cat cat = new Cat(); 
            Mouse mouse1 = new Mouse("mouse1", cat); 
            Mouse mouse2 = new Mouse("mouse2", cat); 
            Master master = new Master(cat); 
            cat.Cry(); 
        } 
    } 


//--------------------------------------------------------------------------------------------- 

设计方法二: 使用event -- delegate设计.. 
    public delegate void SubEventHandler(); 
    public abstract class Subject 
    { 
        public event SubEventHandler SubEvent; 
        protected void FireAway() 
        { 
            if (this.SubEvent != null) 
                this.SubEvent(); 
        }   
    } 
    public class Cat : Subject 
    {  
        public void Cry() 
        { 
            Console.WriteLine("cat cryed."); 
            this.FireAway(); 
        } 
    } 
    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 Mouse(string name, Subject sub) : base(sub) 
        {   
            this.name = name; 
        } 
        public override void Response() 
        { 
            Console.WriteLine(name + " attempt to escape!"); 
        } 
    } 
    public class Master : Observer 
    { 
        public Master(Subject sub) : base(sub){} 
        public override void Response() 
        { 
            Console.WriteLine("host waken"); 
        } 
    } 
    class Class1 
    { 
        static void Main(string[] args) 
        { 
            Cat cat = new Cat(); 
            Mouse mouse1 = new Mouse("mouse1", cat); 
            Mouse mouse2 = new Mouse("mouse2", cat); 
            Master master = new Master(cat); 
            cat.Cry(); 
        } 

    }

//中国移动的例子

namespace ConsoleApplication1
{
    public interface IObserver
    {
        void Reply();        }

    public interface ISub
    {
        void AddIn(IObserver ob);
    }

    public class user : IObserver
    {
        private string no;

        public string No { get { return no; } }
        //构造时被加入到chinamobile
        public user(string no, ISub sub)
        {
            this.no = no;
            //add in 
            sub.AddIn(this);
        }

        public void Reply()
        {
            Console.WriteLine(this.no + " reply");
        }
    }

    public class chinamobile:ISub
    {
        private ArrayList list = new ArrayList();

        public void AddIn(IObserver ob)
        {
            list.Add(ob);
        }

        public void send()
        {
            foreach (IObserver i in list)
            {
                //Console.WriteLine("Send to :" + i.No);
                i.Reply();
            }
        }
    }    
    class MainClass
    {
        static void Main(string[] args)
        {
            chinamobile cm = new chinamobile();
            user u1 = new user("111", cm);
            user u2 = new user("222", cm);
            user u3 = new user("333", cm);
            cm.send();
        }
    } 
   

}