设计模式笔记2：策略模式

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace 策略模式
 8 {
 9     // 核心类，定义了具体实现功能。算法的不同实现由各个类来完成。
10     abstract class CashSuper
11     {
12         public abstract double AcceptCash(double money);
13     }
14 
15     class CashNormal : CashSuper
16     {
17         public override double AcceptCash(double money)
18         {
19             return money;
20         }
21     }
22 
23     class CashRebate : CashSuper
24     {
25         private double rebate = 1.0d;
26         public CashRebate(double rebate)
27         {
28             this.rebate = rebate;
29         }
30         public override double AcceptCash(double money)
31         {
32             return this.rebate * money;
33         }
34     }
35 
36     class CashReturn : CashSuper
37     {
38         private double moneyCondition;
39         private double moneyReturn;
40 
41         public CashReturn(double moneyCondition, double moneyReturn)
42         {
43             this.moneyCondition = moneyCondition;
44             this.moneyReturn = moneyReturn;
45         }
46 
47         public override double AcceptCash(double money)
48         {
49             return money - (int)(money / this.moneyCondition) * this.moneyReturn;
50         }
51     }
52 
53 
54 
55 }

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace 策略模式
 8 {
 9     class CashContext
10     {
11         private CashSuper cs;
12         // 运用到了简单工厂，根据条件创建指定对象。可用发射优化。
13         public CashContext(string type)
14         {
15             switch (type)
16             {
17                 case "不打折": cs = new CashNormal();
18                     break;
19                 case "九折": cs = new CashRebate(0.9d);
20                     break;
21                 case "五折": cs = new CashRebate(0.5d);
22                     break;
23                 case "满300返100": cs = new CashReturn(300, 100);
24                     break;
25             }
26         }
27 
28         public double GetResult(double money)
29         {
30             return cs.AcceptCash(money);
31         }
32 
33     }
34 }

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace 策略模式
 8 {
 9     class Program
10     {
11         static void Main(string[] args)
12         {
13             while (true)
14             {
15                 Console.WriteLine("请输入金额：");
16                 double money = double.Parse(Console.ReadLine());
17                 Console.WriteLine("请选择打折方式：1.不打折    2.九折    3.五折    4.满300返100");
18                 int index = int.Parse(Console.ReadLine()) - 1;
19                 string type = new String[] { "不打折", "九折", "五折", "满300返100" }[index];
20                 // 计算价格
21                 Console.WriteLine("你需要付款：" + new CashContext(type).GetResult(money));
22                 Console.ReadKey(true);
23             }
24 
25 
26 
27         }
28     }
29 }