聯動效應，只要執行Cat.Cryed()就可以使老鼠逃跑，主人驚醒。(

using System;
using System.Collections;

namespace ConsoleApplication1
{
 /// <summary>
 /// Class1 的摘要說明。
 /// </summary>
// class Class1
// {
//  /// <summary>
//  /// 應用程序的主入口點。
//  /// </summary>
//  [STAThread]
//  static void Main(string[] args)
//  {
//   //
//   // TODO: 在此處添加代碼以啓動應用程序
//   //
//  }
// }
// public abstract class A
// {
//  public A()
//  {
//   Console.WriteLine('a');
//  }
//  public virtual void Fun()
//  {
//   Console.WriteLine("A.Fun()");
//  }
// }
//
// public class B: A
// {
//  public B()
//  {
//   Console.WriteLine('b');
//  }
//
//  public new void Fun()
//  {
//   Console.WriteLine("B.Fun()");
//  }
//
//  public static void Main()
//  {
//   A a = new B();
//   a.Fun();
//  }
// }
// public class A
// {
//  public virtual void Fun1(int i)
//  {
//   Console.WriteLine(i);
//  }
//
//  public void Fun2(A a)
//  {
//   a.Fun1(1);
//   Fun1(5);
//  }
// }
//
//
// public class B : A
// {
//  public override void Fun1(int i)
//  {
//   base.Fun1 (i + 1);
//  }
//
//  public static void Main()
//  {
//   B b = new B();
//   A a = new A();
//   a.Fun2(b);
//   b.Fun2(a);
//  }
// }

// public class myClass
// {
//  public static int func( int j){
//   
////   func(1)=1;
////   func(2)=1;
//   int fun=1;
//   if (j<3) return 1;
//   //for ( int i=0; i<j+1;i++){
//   //func(j)=
//    return (func(j-1)+func(j-2));
//   //}
//   //return func(j);
//
//  }
//  public static void Main(){
//   Console.WriteLine("end ");
//   int me=func(4);
//    Console.WriteLine(me);
//     //((string)func(4));
//  }
// }

 public interface Observer
 {
  void Response(); //觀察者的響應，如是老鼠見到貓的反映
 }
 public interface Subject
 {
  void AimAt(Observer obs); //針對哪些觀察者，這裏指貓的要撲捉的對象---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();
  }
 }

 

}