C++对象生命周期

 1 
 2 #include <stdio.h>
 3 #include <stdlib.h>
 4 
 5 class Parent
 6 {
 7 public:
 8 Parent(){_static = this;}
 9 ~Parent(){}
10 virtual void print();
11 static Parent* _static;
12 };
13 
14 void Parent::print()
15 {
16 printf("print Parent!\n");
17 }
18 Parent* Parent::_static = NULL;
19 
20 Parent* getInstance(){return Parent::_static;}
21 
22 class Child:
23 public Parent
24 {
25 public:
26 Child(){}
27 ~Child(){}
28 virtual void print();
29 };
30 
31 void Child::print()
32 {
33 printf("print Child!\n");
34 }
35 
36 class Child2:
37 public Child
38 {
39 public:
40 Child2(){}
41 ~Child2(){}
42 virtual void print();
43 };
44 
45 void Child2::print()
46 {
47 printf("print Child2!\n");
48 }
49 
50 Child2 _child;
51 
52 int main()
53 {
54 Parent* _ins = getInstance();
55 _ins->print();
56 system("pause");
57 return 0;
58 }