/*函数指针模拟类和继承的程序例子,
同时还示例了#pragma pack的用法*/
#include <stdio.h>
void f1(void)
{
printf("f1 ");
}
void f2(void)
{
printf("f2 ");
}
void f3(void)
{
printf("f3 ");
}
/*以下用两个结构体来模拟类和类继承,即每个结构体有成员变量
和成员函数,menu结构体可以访问baseclass的成员变量和函数,
相当于继承了bseclass*/
#pragma pack(push, 1)
typedef struct test
{
unsigned char a;
unsigned char b;
unsigned int c;
int d:1;
}test;
/*在#pragma pack(push,1)和#pragma pack(pop)之间的结构体按1字节压缩存放
#pragma pack(1)后面所以的都要按1字节压缩存放menu“类”可以访问基类
“baseclass”成员*/
#pragma pack(pop)
#pragma pack(1)
typedef struct baseclass
{
char *basename;
char c;
void (*baseFun)(void);
}baseclass;
typedef struct menu
{
char *name;
int x;
int y;
baseclass *bc;
void (*OkFun)(void);
void (*CanFun)(void);
}menu;
int main()
{
void (*pf[3])(void) = //函数指针数组
{ f1,
f2,
f3
};
void (*fp)(void);
int i;
baseclass *bc = (baseclass*)malloc(sizeof(baseclass));
bc->basename = "basename";
bc->baseFun = f3;
test test;
menu menulist[4] =
{
{"menu1", 1, 1, bc, f1, f2},
{"menu2", 2, 2, bc, f1, f2},
{"menu3", 3, 3, bc, f1, f2},
{"menu3", 4, 4, bc, f1, f2}
};
for(i = 0; i < 3; i++)
{
printf(menulist[i].name);
printf(" ");
printf("%d %d %s ",menulist[i].x,menulist[i].y,menulist[i].bc->basename);
menulist[i].OkFun();
menulist[i].CanFun();
menulist[i].bc->baseFun();
printf("/n");
}
printf("sizeof(test):%d/n", sizeof(test));
printf("sizeof(baseclass): %d/n", sizeof(baseclass));
printf("sizeof(menu): %d", sizeof(menu));
free(bc);
return 1;
}