c++ 行为型模式-命令(Command)

 1 #include <iostream>
 2 #include <list>
 3 class  Receiver
 4 {
 5 public:
 6     Receiver() {}
 7     virtual ~Receiver() {}
 8     void  Action()
 9     {
10         std::cout << "Receiver Action" << std::endl;
11     }
12 };
13 class  Command
14 {
15 public:
16     Command(){}
17     virtual ~Command() {}
18     virtual void  Execute() = 0;
19 };
20 class  ConcreateCommand : public Command
21 {
22 public:
23     ConcreateCommand(Receiver* ptr) :m_pReceiver(ptr) {}
24     virtual ~ConcreateCommand() 
25     {
26         if (m_pReceiver) delete m_pReceiver;
27     }
28     virtual void  Execute()
29     {
30         if (m_pReceiver)
31         {
32             m_pReceiver->Action();
33         }
34     }
35 private:
36     Receiver* m_pReceiver;
37 };
38 class  Invoker
39 {
40 public:
41     Invoker(Command* ptr) :m_pCommand(ptr) {}
42     virtual ~Invoker() 
43     {
44         if (m_pCommand) delete m_pCommand;
45     }
46     void  Invoke()
47     {
48         if (m_pCommand)
49         {
50             m_pCommand->Execute();
51         }
52     }
53 private:
54     Command* m_pCommand;
55 };
56 
57  int main()
58  {
59      Receiver* ptr1 = new Receiver();
60      Command* ptr2 = new ConcreateCommand(ptr1);
61      Invoker* ptr3 = new Invoker(ptr2);
62      ptr3->Invoke();
63      delete ptr3;
64      system("pause");
65  }