设计模式1——抽象工厂

抽象工厂通过一个工厂产生各种不同的实际对象，并返回基类的指针，通过基类的指针来统一对对象进行操作，增强了其灵活性，降低了耦合，便于后续更新和维护。

实例代码：

AbstractFactory.h内容

 1 #ifndef AbstractFactory_H_H
 2 #define AbstractFactory_H_H
 3
 4 #include <iostream>
 5 using namespace std;
 6
 7 class Oper
 8 {
 9 public:
10     Oper(int a0, int b0) : a(a0), b(b0) {}
11     virtual ~Oper() {}
12     virtual int getResult() = 0;
13
14
15 protected:
16     int a, b;
17 };
18
19 class OperAdd : public Oper
20 {
21 public:
22     OperAdd(int a0, int b0) : Oper(a0, b0) {}
23     virtual int getResult(){
24         return a+b;
25     }
26 };
27
28 class OperSub : public Oper
29 {
30 public:
31     OperSub(int a0, int b0) : Oper(a0, b0) {}
32     virtual int getResult(){
33         return a-b;
34     }
35 };
36
37 class AbstractFactory
38 {
39 public:
40     static Oper* create(int a0, int b0, char ch){
41         Oper *oper = NULL;
42         switch(ch){
43         case ‘+‘: oper = new OperAdd(a0, b0); break;
44         case ‘-‘: oper = new OperSub(a0, b0); break;
45         }
46         return oper;
47     }
48 };
49
50
51 void AbstractFactoryTest()
52 {
53     int a = 4, b = 3;
54     //Oper *oper = NULL;
55     cout << AbstractFactory::create(a, b, ‘+‘)->getResult() << endl;
56     cout << AbstractFactory::create(a, b, ‘-‘)->getResult() << endl;
57 }
58
59
60 #endif

具体运行在main函数中调用AbstractFactoryTest()即可。