小白求大佬帮我解决下这个结构体指针问题

Question

// ********************************** 通讯录.h  文件  *********************************
#pragma once
#define MAX_name 20
#define MAX_sex  5
#define MAX_tele  15
#define MAX_addr  30
#define DEFAULT_SZ 3

struct PeoInfo
{
	char name[MAX_name];
	int age;
	char sex[MAX_sex];
	char tele[MAX_tele];
	char addr[MAX_addr];
};
enum Option
{
	EXIT,
	ADD,
	DEL,
	SEARCH,
	MODIFY,
	SHOW,
	SORT
};

struct Contact    // 通讯录的类型
{
	struct PeoInfo* data;  
	int size;   //  记录当前已经有的元素个数
	int capacity;// 当前data里的最大容量
};

void InitContact(struct Contact* ps);
void AddContact(struct Contact* ps);
void ShowContact(const struct Contact* ps);
void DelContact(struct Contact* ps);
void SearchContact(const struct Contact* ps);
void ModifyContact(struct Contact* ps);
void SortContact(struct Contact* ps);
void DestroyContact(struct Contact* ps);



//  **************************   通讯录.cpp  **************************************

#define _CRT_SECURE_NO_WARNINGS 1
#include"通讯录.h"
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<search.h>

void InitContact(struct Contact* ps)
{
	//memset(ps->data, 0, sizeof(ps->data));
	//ps->size = 0;   //初始化通讯录 全部为 0
	ps->data = (struct PeoInfo*)malloc(3 * sizeof(struct PeoInfo));
	if (ps->data == NULL)
	{
		return;
	}
	ps->size = 0;
	ps->capacity = DEFAULT_SZ;
} 
void CheckCapacity(struct Contact* ps)
{
	if (ps->size == ps->capacity)
	{
		//增容
		struct PeoInfo* ptr=(struct PeoInfo*)realloc(ps->data, (ps->capacity + 2) * sizeof(struct PeoInfo));
		if (ptr != NULL)
		{
			ps->data = ptr;
			ps->capacity += 2;
			printf("增容成功！\n");
		}
		else
			printf("增容失败！\n");
	}
}
void AddContact(struct Contact* ps)
{
	//检测当前空间是否满了：如果满了，扩容；如果不满，退出，进行下一步
	CheckCapacity(ps);
	printf("请输入姓名：");
	scanf("%s", ps->data[ps->size].name);
	printf("请输入年龄：");
	scanf("%d", &(ps->data[ps->size].age));
	printf("请输入性别：");
	scanf("%s", ps->data[ps->size].sex);
	printf("请输入电话：");
	scanf("%s", ps->data[ps->size].tele);
	printf("请输入地址：");
	scanf("%s", ps->data[ps->size].addr);
	ps->size++;
	printf("添加成功！\n");
}

//  ******** 使用qsort 对通讯录排序******
int cmp_by_name(const void* e1, const void* e2)
{
	//return strcmp(((struct Contact*)e1)->data.name, ((struct Contact*)e2)->data.name);
	return strcmp(((struct Contact*)e1)->data->name, (((struct Contact*)e2)->data->name));
}
void SortContact(struct Contact* ps)
{
	qsort(ps->data, ps->size, sizeof(ps->data[0]), cmp_by_name);
}
void DestroyContact(struct Contact* ps)
{
	free(ps->data);
	ps->data = NULL;
} 

void ShowContact(const struct Contact* ps)
{
	if (ps->size == 0)
	{
		printf("通讯录为空！\n");
	}
	else
	{
		int i = 0;
		printf("%20s\t%4s\t%5s\t%12s\t%20s\n", "名字", "年龄", "性别", "电话", "地址");
		for (i = 0; i < ps->size; i++)
		{
			printf("%20s\t%4d\t%5s\t%12s\t%20s\n", ps->data[i].name,
				ps->data[i].age,
				ps->data[i].sex,
				ps->data[i].tele,
			    ps->data[i].addr);
		}
	}
}
static int Findbyname(const struct Contact* ps, char* name)
{
	int i = 0;
	for (i = 0; i < ps->size ; i++)
	{
		if (strcmp(ps->data[i].name, name) == 0)
			return i;
	}
	return -1;  //找不到
}
void DelContact(struct Contact* ps)
{
	char name[MAX_name] = { 0 };
	printf("请输入要删除人的名字：");
	scanf("%s", name);
	int pos=Findbyname(ps,name);
	if (pos == -1)
	{
		printf("要删除的人不存在！\n");
	}
	else
	{
		int i = 0;
		for (i = pos; i < ps->size-1; i++)
		{
			 ps->data[i] = ps->data[i + 1];
		}
		ps->size--;
		printf("删除成功！\n");
	}
}
void SearchContact(const struct Contact* ps)
{
	char name[MAX_name] = { 0 };
	printf("请输入要查找人的名字：");
	scanf("%s", name);
	int pos = Findbyname(ps, name);
	if (pos == -1)
	{
		printf("要查找人的信息不存在！");
	}
	else
	{
		printf("%20s\t%4s\t%5s\t%12s\t%20s\n", "名字", "年龄", "性别", "电话", "地址");
		printf("%20s\t%4d\t%5s\t%12s\t%20s\n", ps->data[pos].name,
			ps->data[pos].age,
			ps->data[pos].sex,
			ps->data[pos].tele,
			ps->data[pos].addr);
	}
}
void ModifyContact(struct Contact* ps)
{
	char name[MAX_name] = { 0 };
	printf("请输入要修改人的姓名：");
	scanf("%s", name);
	int pos = Findbyname(ps, name);
	if (pos == -1)
	{
		printf("被修改人的信息不存在");
	}
	else
	{
		printf("请输入姓名：");
		scanf("%s", ps->data[pos].name);
		printf("请输入年龄：");
		scanf("%d", &(ps->data[pos].age));
		printf("请输入性别：");
		scanf("%s", ps->data[pos].sex);
		printf("请输入电话：");
		scanf("%s", ps->data[pos].tele);
		printf("请输入地址：");
		scanf("%s", ps->data[pos].addr);
		printf("修改成功！\n");
	}
}





//****************************  test.cpp  ********************************************** 

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<string.h>
#include"通讯录.h"

void menu()
{
	printf("***************************************************\n");
	printf("******* 1.ADD                   2.DEL ************\n");
	printf("******* 3.SEARCH               4.MODIFY ***********\n");
	printf("******* 5.SHOW                  6.SORT ************\n");
	printf("***************  0.EXIT    ************************\n");
	printf("***************************************************\n");

}
int main()
{
	int input = 0;
	struct Contact con;  //con 就是通讯录，其中包含了data 指针、size和capacity
	InitContact(&con);//初始化通讯录

	do
	{
		menu();
		printf("请选择:");
		scanf("%d", &input);
		switch (input)
		{
		case ADD:
			AddContact(&con);
			break;
		case DEL:
			DelContact(&con);
			break;
		case SEARCH:
			SearchContact(&con);
			break;
		case MODIFY:
			ModifyContact(&con);
			break;
		case SHOW:
			ShowContact(&con);
			break;
		case SORT:
			SortContact(&con);
			break;
		case EXIT:
			//销毁通讯录------释放动态内存开辟的内存
			DestroyContact(&con);
			printf("退出通讯录!");
			break;
		default:
				printf("输入错误，请重新输入:");
			break;
		}
	} while (input);
	return 0;
}

本人小白，刚学习C语言，近期学习了动态内存分配，看着视频写了这个动态内存版本的通讯录。现在这个通讯录其他功能都可以实现，就是这个排序功能现在实现不了了。之前struct Contact  con中创建的是 struct PeoInfo  data[1000] ，使用这个结构体数组的话，排序功能可以跑起来，但是现在改成struct PeoInfo*  data 后，排序功能不能正常使用。求大佬，帮我解答下。

Answer 1

int cmp_by_name(const void* e1, const void* e2)
{
	//return strcmp(((struct Contact*)e1)->data.name, ((struct Contact*)e2)->data.name);
	return strcmp(((struct Contact*)e1)->data->name, (((struct Contact*)e2)->data->name));
}

改成

int cmp_by_name(const void* e1, const void* e2)
{
	//return strcmp(((struct Contact*)e1)->data.name, ((struct Contact*)e2)->data.name);
	return strcmp(((struct PeoInfo*)e1)->name, (((struct PeoInfo*)e2)->name));
}

试试看