1 //现金收费抽象类  2     abstract class CashSuper   3     {  4         //现金收取超类的抽象方法，收取现金，参数为原价，返回为当前价  5         public abstract double acceptCash(double money);  6     }
  7 //正常收费子类  8     class CashNormal:CashSuper  9     { 10         //正常收费，原价返回 11         public override double acceptCash(double money) 12         { 13             return money; 14         } 15 　　　}
 16 //打折收费子类 17     class CashRebate:CashSuper 18     { 19         private double moneyRebate = 1d; 20         //打折收费，初始化时，必须要输入折扣率，如八折，就是0.8 21         public CashRebate(string moneyRebate) 22         { 23             this.moneyRebate = double.Parse(moneyRebate); 24         } 25         public override double acceptCash(double money) 26         { 27             return money * moneyRebate; 28         } 29 　　　}
 30 //返利收费子类 31     class CashReturn:CashSuper 32     {         33         private double moneyCondition = 0.0d; 34         private double moneyReturn = 0.0d; 35         //返利收费，初始化时必须要输入返利条件和返利值 36         //比如满300返100，则moneyCondition为300，moneyReturn为100 37         public CashReturn(string moneyCondition, string moneyReturn) 38         { 39             this.moneyCondition = double.Parse(moneyCondition); 40             this.moneyReturn = double.Parse(moneyReturn); 41         } 42         public override double acceptCash(double money) 43         { 44             double result = money; 45             //若大于返利条件则需要减去返利值 46             if (money >= moneyCondition) 47             { 48                 result = money - Math.Floor(money/moneyCondition)*moneyReturn; 49             } 50             return result; 51         } 52 　　　} 53 //只是策略模式 54     //class CashContext 55     //{ 56     //    //声明一个CashSuper对象 57     //    private CashSuper cs; 58     //    //通过构造方法，传入具体的收费策略 59     //    public CashContext(CashSuper csuper) 60     //    { 61     //        this.cs = csuper; 62     //    } 63     //    //根据收费策略的不同，获得计算结果 64     //    public double GetResult(double money) 65     //    { 66     //        return cs.acceptCash(money); 67     //    } 68     //} 69  70 //策略与简单工厂结合 71     class CashContext 72     { 73         CashSuper cs = null; 74         //注意参数不是具体的收费策略对象，而是一个字符串，表示收费类型 75         //将实例化具体策略的过程由客户端转移到Context类中。简单工厂的应用 76         public CashContext(string type) 77         { 78             switch (type) 79             { 80                 case "正常收费": 81                     CashNormal cs0 = new CashNormal(); 82                     cs = cs0; 83                     break; 84                 case "满300返100": 85                     CashReturn cs1 = new CashReturn("300","100"); 86                     cs = cs1; 87                     break; 88                 case "打8折": 89                     CashRebate cs2 = new CashRebate("0.8"); 90                     cs = cs2; 91                     break; 92             } 93         } 94         public double GetResult(double money) 95         { 96             return cs.acceptCash(money); 97         } 98 　　　}
　　　　 99 //客户端调用100         CashContext csuper = new CashContext(cbxType.SelectedItem.ToString());101         Double totalPrice = 0d;102         totalPrice = csuper.GetResult(Convert.ToDouble(txtPrice.Text) * Convert.ToDouble(txtNum.Text));