c++ 结构型模式-装饰(Decorator)

 1 #include <iostream>
 2 #include <list>
 3 class  Component
 4 {
 5 public:
 6     Component() {}
 7     virtual ~Component() {}
 8     virtual void  Operation() = 0;
 9 };
10 class  ConcreteComponent : public Component
11 {
12 public:
13     virtual void  Operation()
14     {
15         std::cout << "print by ConcreteComponent" << std::endl;
16     }
17 };
18 
19 class  Decorator : public Component
20 {
21 public:
22     Decorator(Component* com) :m_com(com) {}
23     virtual ~Decorator() {}
24     virtual void  Operation() = 0;
25     Component* m_com;
26 };
27 class  ConcreteDecoratorA : public Decorator
28 {
29 public:
30     ConcreteDecoratorA(Component* com) :Decorator(com) {}
31     virtual ~ConcreteDecoratorA() {}
32     virtual void  Operation()
33     {
34         m_com->Operation();
35         addState();
36     }
37     void addState()
38     {
39         std::cout << "addState" << std::endl;
40     }
41 };
42 class  ConcreteDecoratorB : public Decorator
43 {
44 public:
45     ConcreteDecoratorB(Component* com) :Decorator(com) {}
46     virtual ~ConcreteDecoratorB() {}
47     virtual void  Operation()
48     {
49         m_com->Operation();
50         addBehavior();
51     }
52     void addBehavior()
53     {
54         std::cout << "addBehavior" << std::endl;
55     }
56 };
57 
58  int main()
59  {
60      Component* ptr = new ConcreteComponent();
61      Component* ptr1 = new ConcreteDecoratorA(ptr);
62      Component* ptr2 = new ConcreteDecoratorB(ptr1);
63      ptr2->Operation();
64      delete ptr2;
65      delete ptr1;
66      delete ptr;
67      system("pause");
68  }