一個網上流傳的貓叫導致的聯動的例題的解決方案

在網上看到這樣一道題目，也有很多人已經給出答案了，整理下，感覺還挺有意思的。

 

題目：

程序設計: 貓大叫一聲，所有的老鼠都開始逃跑，主人被驚醒

要求： 

1.要有聯動性，老鼠和主人的行爲是被動的。

2.考慮可擴展性，貓的叫聲可能引起其他聯動效應。 

 

方法一：使用C#的委託與事件實現

using System; using System.Collections.Generic; using System.Text; namespace TestApplication.CatMouse { public delegate void TestEventHandler(); public abstract class Subject { public event TestEventHandler TestEvent; public void Activation() { if (TestEvent != null) { this.TestEvent(); } } } public class Cat : Subject { private string name; public Cat(string name) { this.name = name; } public void Shouted() { Console.WriteLine(name + " Cat shouted!"); Console.WriteLine("=============下面是聯動效應==============="); this.Activation(); } } public abstract class Observer { public Observer(Subject sub) { sub.TestEvent += new TestEventHandler(Response); } public virtual 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 + " tried to escape "); } } public class Master : Observer { private string name; public Master(string name,Subject sub) : base(sub) { this.name = name; } public override void Response() { Console.WriteLine(name +" waken up!"); } } public class Test { public static void Main(string[] args) { Cat cat = new Cat("ABC"); Mouse m1 = new Mouse("Mouse1", cat); Mouse m2 = new Mouse("Mouse2", cat); Master host = new Master("Mr.Li",cat); cat.Shouted(); Console.ReadLine(); } } }

方法二：採用傳統的加入事件的方法

待續。。。