备忘录模式

 1 // 备忘录模式.cpp : 定义控制台应用程序的入口点。
 2 //
 3 
 4 #include "stdafx.h"
 5 #include<iostream>
 6 #include<string>
 7 using namespace std;
 8 class Memento
 9 {
10 private:
11     string state;
12 public:
13     Memento(string s)
14     {
15         state=s;
16     }
17     ~Memento(){}
18     string get()
19     {
20         return state;
21     }
22 };
23 
24 class Originator
25 {
26 private:
27     string state;//需要备份的内容
28 public:
29     Originator(){}
30     ~Originator(){}
31     void set_state(string s)
32     {
33         state=s;
34     }
35     void show_state()
36     {
37         cout<<state<<endl;
38     }
39     Memento * creat_Memento()  //备份状态
40     {
41         return new Memento(state);
42     }
43     void revover_state(Memento* s)//恢复状态
44     {
45         state=s->get();
46     }
47 };
48 
49 class Caretaker
50 {
51 private:
52     Memento * memento;
53 public:
54     Caretaker(){}
55     ~Caretaker(){}
56     void set(Memento * m)
57     {
58         memento=m;
59     }
60     Memento* get()
61     {
62         return memento;
63     }
64 };
65 
66 int _tmain(int argc, _TCHAR* argv[])
67 {
68     Originator* led=new Originator();3
69     led->set_state("on");
70 
71     Caretaker *save=new Caretaker();
72     save->set(led->creat_Memento());//备份
73     led->show_state();
74 
75     led->set_state("off");
76     led->show_state();
77 
78     led->revover_state(save->get());
79     led->show_state();
80 
81     return 0;
82 }