程序设计之猫鼠人

程序设计: 猫大叫一声，所有的老鼠都开始逃跑，主人被惊醒。(C#语言)

要求：  1.要有联动性，老鼠和主人的行为是被动的。

2.考虑可扩展性，猫的叫声可能引起其他联动效应。

 

 

 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)

 

 1     public interface Observer
 2     {
 3         void Response();    //观察者的响应，如是老鼠见到猫的反映
 4     }
 5     public interface Subject
 6     {
 7         void AimAt(Observer obs);  //针对哪些观察者，这里指猫的要扑捉的对象---老鼠
 8     }
 9     public class Mouse : Observer
10     {
11         private string name;
12         public Mouse(string name, Subject subj)
13         {
14             this.name = name;
15             subj.AimAt(this);
16         }
17 
18         public void Response()
19         {
20             Console.WriteLine(name + " attempt to escape!");
21         }
22     }
23     public class Master : Observer
24     {
25         public Master(Subject subj)
26         {
27             subj.AimAt(this);
28         }
29 
30         public void Response()
31         {
32             Console.WriteLine("Host waken!");
33         }
34     }
35 
36     public class Cat : Subject
37     {
38         private ArrayList observers;
39         public Cat()
40         {
41             this.observers = new ArrayList();
42         }
43         public void AimAt(Observer obs)
44         {
45             this.observers.Add(obs);
46         }
47         public void Cry()
48         {
49             Console.WriteLine("Cat cryed!");
50             foreach (Observer obs in this.observers)
51             {
52                 obs.Response();
53             }
54         }
55     }
56     class MainClass
57     {
58         static void Main(string[] args)
59         {
60             Cat cat = new Cat();
61             Mouse mouse1 = new Mouse("mouse1", cat);
62             Mouse mouse2 = new Mouse("mouse2", cat);
63             Master master = new Master(cat);
64             cat.Cry();
65         }
66     }
67 

 

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

设计方法二: 使用event -- delegate设计..

 

 1     public delegate void SubEventHandler();
 2     public abstract class Subject
 3     {
 4         public event SubEventHandler SubEvent;
 5         protected void FireAway()
 6         {
 7             if (this.SubEvent != null)
 8                 this.SubEvent();
 9         }
10     }
11     public class Cat : Subject
12     {
13         public void Cry()
14         {
15             Console.WriteLine("cat cryed.");
16             this.FireAway();
17         }
18     }
19     public abstract class Observer
20     {
21         public Observer(Subject sub)
22         {
23             sub.SubEvent += new SubEventHandler(Response);
24         }
25         public abstract void Response();
26     }
27     public class Mouse : Observer
28     {
29         private string name;
30         public Mouse(string name, Subject sub)
31             : base(sub)
32         {
33             this.name = name;
34         }
35         public override void Response()
36         {
37             Console.WriteLine(name + " attempt to escape!");
38         }
39     }
40     public class Master : Observer
41     {
42         public Master(Subject sub) : base(sub) { }
43         public override void Response()
44         {
45             Console.WriteLine("host waken");
46         }
47     }
48     class Class1
49     {
50         static void Main(string[] args)
51         {
52             Cat cat = new Cat();
53             Mouse mouse1 = new Mouse("mouse1", cat);
54             Mouse mouse2 = new Mouse("mouse2", cat);
55             Master master = new Master(cat);
56             cat.Cry();
57         }
58 
59     }
60