1.結構體內嵌結構體時,內嵌結構體成員與結構體其它成員依次存儲,地址連續
2.void型指針作爲形參傳遞後,在子函數內可以被轉換成任意類型解引用,如下:DQP結構體類型的void指針
先強制轉換爲int *,再轉換爲DQP *。
#include <stdio.h>
#include <stdlib.h>
typedef struct
{
int dp;
struct arg
{
int arg_w;
int arg_h;
int arg_f;
}arg;
}DQP;
void func(void *p)
{
int *a;
DQP *b;
a=(int *)p;
printf("<func>%p\n",a);
printf("a=%d\n",*a);
b=(DQP *)p;
printf("dp=%d,w=%d,h=%d,f=%d\n",
b->dp,b->arg.arg_w,b->arg.arg_h,b->arg.arg_f);
printf("<func>%p,%p,%p,%p\n",
&b->dp,&b->arg.arg_w,&b->arg.arg_h,&b->arg.arg_f);
}
int main(int argc,char **argv)
{
DQP mode1;
mode1.dp=5;
mode1.arg.arg_w=10;
mode1.arg.arg_h=15;
mode1.arg.arg_f=20;
printf("<main>%p,%p,%p,%p\n",
&mode1.dp,&mode1.arg.arg_w,&mode1.arg.arg_h,&mode1.arg.arg_f);
func((void *)&mode1);
return 0;
}
輸出:
<main>0x7ffd114325e0,0x7ffd114325e4,0x7ffd114325e8,0x7ffd114325ec
<func>0x7ffd114325e0
a=5
dp=5,w=10,h=15,f=20
<func>0x7ffd114325e0,0x7ffd114325e4,0x7ffd114325e8,0x7ffd114325ec