1.结构体内嵌结构体时，内嵌结构体成员与结构体其它成员依次存储，地址连续 2.void型指针作为形参传递后，在子函数内可以被转换成任意类型解引用，如下：DQP结构体类型的void指针 先强制转换为int *，再转换为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; }
输出：
<main>0x7ffd114325e0,0x7ffd114325e4,0x7ffd114325e8,0x7ffd114325ec <func>0x7ffd114325e0 a=5 dp=5,w=10,h=15,f=20 <func>0x7ffd114325e0,0x7ffd114325e4,0x7ffd114325e8,0x7ffd114325ec
