工厂方法模式

最新推荐文章于 2024-10-30 17:12:58 发布

转载最新推荐文章于 2024-10-30 17:12:58 发布 · 54 阅读

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原文链接：http://www.cnblogs.com/-zda/p/7153129.html

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工厂方法模式

　　定义：定义一个用于创建对象的接口，让子类决定实例化哪个类。工厂方法使一个类的实例化延迟到其子类。

　　在这之前学习了简单工厂模式，用简单工厂模式实现了计算器功能。

　　工厂类代码如下：

 1     public class OperationFactory
 2     {
 3         public static Operation CreateOperae(string operate)
 4         {
 5             Operation oper = null;
 6             switch (operate)
 7             {
 8                 case "+":
 9                     oper = new OperationAdd();
10                     break;
11                 case "-":
12                     oper = new OperationSub();
13                     break;
14                 case "*":
15                     oper = new OperationMul();
16                     break;
17                 case "/":
18                     oper = new OperationDiv();
19                     break;
20             }
21             return oper;
22         }
23     }

　　客户端代码：

1             Operation oper;
2             oper = OperationFactory.CreateOperae("+");
3             oper.NumberA = 2;
4             oper.NumberB = 5;
5             double result = oper.GetResult();

　　工厂模式实现：

1     /// <summary>
2     /// 工厂接口
3     /// </summary>
4     interface IFactory
5     {
6         Operation CreateOperation();
7     }

　　构建具体的工厂去实现这个接口

 1     class AddFactory : IFactory
 2     {
 3         public Operation CreateOperation()
 4         {
 5             return new OperationAdd();
 6         }
 7     }
 8 
 9     class SubFactory : IFactory
10     {
11         public Operation CreateOperation()
12         {
13             return new OperationSub();
14         }
15     }
16 
17     class MulFactory : IFactory
18     {
19         public Operation CreateOperation()
20         {
21             return new OperationMul();
22         }
23     }
24 
25     class DivFactory : IFactory
26     {
27         public Operation CreateOperation()
28         {
29             return new OperationDiv();
30         }
31     }

　　客户端代码：

1             IFactory operFactory = new AddFactory();
2             Operation oper = operFactory.CreateOperation();
3             oper.NumberA = 1;
4             oper.NumberB = 2;
5             double result = oper.GetResult();