简单工厂模式 

 1 public class Operation
 2     {
 3         private double _numberA = 0;
 4         private double _numberB = 0;
 5 
 6         public double NumberA
 7         {
 8             get { return _numberA; }
 9             set { _numberA = value; }
10         }
11 
12         public double NumberB
13         {
14             get { return _numberB; }
15             set { _numberB = value; }
16         }
17 
18         public virtual double GetResult()
19         {
20             double result = 0;
21             return result;
22         }
23     }
24 
25     class OperationAdd : Operation
26     {
27         public override double GetResult()
28         {
29             double result = 0;
30             result = NumberA + NumberB;
31 
32             return result;
33         }
34     }
35 
36     class OperationSub : Operation
37     {
38         public override double GetResult()
39         {
40             double result = 0;
41             result = NumberA - NumberB;
42 
43             return result;
44         }
45     }
46 
47     class OperationMul : Operation
48     {
49         public override double GetResult()
50         {
51             double result = 0;
52             result = NumberA * NumberB;
53 
54             return result;
55         }
56     }
57 
58     class OperationDiv : Operation
59     {
60         public override double GetResult()
61         {
62             double result = 0;
63             if (Math.Abs(0 - NumberB) < 0.000001)
64             {
65                 throw new Exception("除数不能为0");
66             }
67 
68             result = NumberA / NumberB;
69 
70             return result;
71         }
72     }
View Code
 1 public class OperationFactory
 2     {
 3         public static Operation createOperate(string operate)
 4         {
 5             Operation oper = null;
 6 
 7             switch (operate)
 8             {
 9                 case "+":
10                     oper = new OperationAdd();
11                     break;
12                 case "-":
13                     oper = new OperationSub();
14                     break;
15                 case "*":
16                     oper = new OperationMul();
17                     break;
18                 case "/":
19                     oper = new OperationDiv();
20                     break;
21             }
22 
23             return oper;
24         }
25     }
View Code

转自《大话设计模式》

posted @ 2017-03-15 01:24  yixiu868  阅读(163)  评论(0)  编辑  收藏  举报