C语言面向对象的简便方法

 1 /************************************************************************/
 2 /*         object    基类                                               */
 3 /************************************************************************/
 4 
 5 
 6 typedef struct stObj OBJECT_STRU;
 7 
 8 typedef char* (*ToString_PF)(void *pObj, char *pcStrBuf);
 9 typedef unsigned int ClassID;
10 
11 struct stObj
12 {
13     ClassID m_uiCID;
14     ToString_PF pfToString;
15 };
16 
17 char* OBJ_ToString(void *pObj, char *pcStrBuf)
18 {
19     sprintf(pcStrBuf, "ClassName:%s;ClassID:%06u", "Object", ((OBJECT_STRU *)pObj)->m_uiCID);
20     return pcStrBuf;
21 }
22 
23 OBJECT_STRU *new_Object()
24 {
25     OBJECT_STRU* pstObj = (OBJECT_STRU*)malloc(sizeof(OBJECT_STRU));
26 
27     if ( NULL == pstObj )
28     {
29         return NULL;
30     }
31 
32     pstObj->m_uiCID = CID_OBJ;
33     pstObj->pfToString = OBJ_ToString;
34 
35     return pstObj;

 1 ==========
 2 
 3 /************************************************************************/
 4 /*         测试                                                         */
 5 /************************************************************************/
 6 
 7 int main()
 8 {
 9     char acStrBuf[200] = {0};
10 
11     OBJECT_STRU *pObj = NULL;
12     ANIMAL_STRU *pAnm = NULL;
13     PLANT_STRU  *pPlt = NULL;
14 
15     // 定义父类
16     OBJECT_STRU *pObj_animal = NULL;
17     OBJECT_STRU *pObj_plant  = NULL;
18 
19     // 父类函数和属性调用
20     pObj = new_Object();
21     printf("[ID = %u][ ToString = %s ]\n", pObj->m_uiCID, pObj->pfToString(pObj, acStrBuf) );
22     free(pObj);
23     pObj = NULL;
24    
25     // 子类函数和属性调用
26     pAnm = new_Animal();
27     strcpy(pAnm->acName,"Panda");
28     printf("%s\n", pAnm->m_stBaseObj.pfToString(pAnm, acStrBuf) );
29     free(pPlt);
30     free(pAnm);
31     pPlt = NULL;
32     pAnm = NULL;
33 
34     // 子类函数和属性调用
35     pPlt = new_Plant();
36     strcpy(pPlt->acName,"Tree");
37     printf("%s\n", pPlt->m_stBaseObj.pfToString(pPlt, acStrBuf) );
38 
39 
40     /************************************************************************/
41     /*  多态测试                                                            */
42     /************************************************************************/
43 
44     // 定义父类
45     // OBJECT_STRU *pObj_animal = NULL;
46     // OBJECT_STRU *pObj_plant  = NULL;
47 
48     // 初始化子类
49     pObj_animal = (OBJECT_STRU *)new_Animal();
50     pObj_plant  = (OBJECT_STRU *)new_Plant();
51 
52     // 执行相同的函数产生不同的效果
53     printf("%s\n", pObj_animal->pfToString(pObj_animal, acStrBuf) );
54     printf("%s\n",  pObj_plant->pfToString(pObj_plant , acStrBuf) );
55 
56     getchar();
57 
58     free(pObj_animal);
59     free(pObj_plant );
60 
61     return 0;
62 }
63