策略模式应用之商场收费系统(C#源代码)

 转自:http://blog.youkuaiyun.com/andylin02/archive/2008/11/14/3302034.aspx

1. using System;
3. namespace CashSystem
4. {
5.     //线程类
6.     class CRunMain
7.     {
8.         public static void ShowMessage()
9.         {
10.             Console.WriteLine("-----------------please input your choise: ------------");
11.             Console.WriteLine("/t/t0. quite");
12.             Console.WriteLine("/t/t1. pay cash noremally");
13.             Console.WriteLine("/t/t2. pya cash in 8 rebate");
14.             Console.WriteLine("/t/t3. pay cash in after 300 return 100");
15.             Console.WriteLine("-------------------------------------------------------");
16.         }
18.         public static int Main()
19.         {
20.             CCashContext objCont = new CCashContext();
21.             CCashSuper objCash = null;
23.             while (true)
24.             {
25.                 int nChoice = 0;
26.                 int nCount = 0;
27.                 double duMoney = 0.0;
28.                 double duPrice = 0.0;
30.                 ShowMessage();
31.                 nChoice = Convert.ToInt32(Console.ReadLine());
33.                 switch (nChoice)
34.                 {
35.                     case 0:
36.                         Console.WriteLine("press any key to quit!");
37.                         Console.Read();
38.                         return 0;
40.                     case 1:
41.                         objCash = new CCashNormal();
42.                         break;
43.                         
44.                     case 2:
45.                         objCash = new CCashRebate(0.8);
46.                         break;
48.                     case 3:
49.                         objCash = new CCashReturn(300, 100);
50.                         break;
52.                     default:
53.                         objCash = null;
54.                         break;
55.                 }
57.                 if (null == objCash)
58.                 {
59.                     Console.WriteLine("input error!");
60.                     continue;
61.                 }
63.                 //set cash object
64.                 objCont.SetBehavior(objCash);
66.                 Console.WriteLine("please input price: ");
67.                 duPrice = Convert.ToDouble(Console.ReadLine());
69.                 Console.WriteLine("please input count: ");
70.                 nCount = Convert.ToInt32(Console.ReadLine());
72.                 duMoney = duPrice * nCount;
74.                 Console.WriteLine("the properly money you should pay is " + objCont.GetResult(duMoney));
75.             }
76.         }
77.     };
79.     //收费策略Context
80.     class CCashContext
81.     {
82.         //设置策略行为，参数为具体的现金收费子类（正常，打折或返利）
83.         public void SetBehavior(CCashSuper objCash)
84.         {
85.             this.m_objCash = objCash;
86.         }
88.         public double GetResult(double duMoney)
89.         {
90.             if (null == this.m_objCash)
91.             {
92.                 Console.WriteLine("null == m_objCash");
93.                 return 0;
94.             }
96.             return this.m_objCash.AcceptCash(duMoney);
97.         }
99.         private CCashSuper m_objCash;
100.     };
102.     abstract class CCashSuper
103.     {
104.         public abstract double AcceptCash(double duMoney);
105.     };
107.     class CCashReturn:CCashSuper
108.     {
109.         public CCashReturn(double duCondition, double duReturn)
110.         {
111.             this.m_duCondition = duCondition;
112.             this.m_duReturn = duReturn;
113.         }
115.         public override double AcceptCash(double duMoney)
116.         {
117.             if (duMoney > this.m_duCondition)
118.             {
119.                 duMoney -= this.m_duReturn;
120.             }
122.             return duMoney;
123.         }
125.         private double m_duCondition = 0.0;
126.         private double m_duReturn = 0.0;
127.     };
129.     class CCashNormal:CCashSuper
130.     {
131.         public override double AcceptCash(double duMoney)
132.         {
133.             return duMoney;
134.         }
136.     };
138.     class CCashRebate:CCashSuper
139.     {
140.         public CCashRebate(double duRebate)
141.         {
142.             this.m_duRebate = duRebate;
143.         }
145.         public override double AcceptCash(double duMoney)
146.         {
147.             return duMoney * this.m_duRebate;
148.         }
151.         private double m_duRebate;
152.     };
153. }