C struct 隐藏结构体成员

//obj.h

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct Obj Obj;

Obj * CreateObject(int id, const char * name);

void PrintObject(Obj * obj);

int GetId(Obj * obj);

char * GetName(Obj * obj);


//obj.c

#include "obj.h"

struct Obj {
    int id;
    char name[32];
};

Obj * CreateObject(int id, const char * name)
{
    Obj * ret = (Obj*)malloc(sizeof(Obj));
    if (ret)
    {
        ret->id = id;
        strcpy_s(ret->name, 32, name);
    }
    return ret;
}

void PrintObject(Obj * obj)
{
    printf("obj->id = %d, obj->name = %s
", obj->id, obj->name);
}

int GetId(Obj * obj)
{
    return obj->id;
}

char * GetName(Obj * obj)
{
    return obj->name;
}

//main.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "obj.h"

int main()
{
    Obj * o1 = NULL;
    Obj * o2 = NULL;

    char name[32] = "two";
    o1 = CreateObject(10, "ten");
    o2 = CreateObject(2, name);

    PrintObject(o1);
    PrintObject(o2);

    printf("o1->id = %d, o1->name = %s
", GetId(o1), GetName(o1));

    puts("
按回车键继续");
    getchar();
    return 0;
}