C语言:动态内存文件储存通讯录

实现一个通讯录；
通讯录可以用来存储人的信息，每个人的信息包括：
姓名、性别、年龄、电话、住址
提供方法：

1. 添加联系人信息
2. 删除指定联系人信息
3. 查找指定联系人信息
4. 修改指定联系人信息
5. 显示所有联系人信息
6. 清空所有联系人
7. 以名字排序所有联系人
8. 保存联系人到文件并退出程序
9. 加载联系人

在第一次写通讯录时 , 设置了人数上限一千 , 并且不可保存 , 程序退出后添加的联系人就失效了 , 但是搭建起来的通讯录框架为后续功能提供了很好的基础

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

#define MAX_PERSON_INFO_SIZE 1000
#define MAX_DATA_SIZE 1024

typedef struct PersonInfo{
    char name[MAX_DATA_SIZE];
    char phone[MAX_DATA_SIZE];
    char sex[MAX_DATA_SIZE];
    char age[MAX_DATA_SIZE];
    char address[MAX_DATA_SIZE];
}PersonInfo;

typedef struct AddressBook{
    PersonInfo person [MAX_PERSON_INFO_SIZE];
    //[0,size)
    int size;
}AddressBook;

AddressBook g_address_book;//g表示全局变量

void Init(){
    for (int i = 0; i <MAX_PERSON_INFO_SIZE ; ++i) {
        g_address_book.person[i].name[0]='\0';
        g_address_book.person[i].phone[0]='\0';
        g_address_book.person[i].sex[0]='\0';
        g_address_book.person[i].age[0]='\0';
        g_address_book.person[i].address[0]='\0';
    }
}

int Menu(){
    printf("==========================\n");
    printf("1.新增联系人\n");
    printf("2.删除联系人\n");
    printf("3.查找联系人\n");
    printf("4.更新联系人信息\n");
    printf("5.打印全部联系人\n");
    printf("6.排序联系人\n");
    printf("7.清空联系人\n");
    printf("0.退出\n");
    printf("==========================\n");
    printf("请输入您的选择:");
    int choice=0;
    scanf("%d",&choice);
    return choice;
}


void Empty(){
    //这个函数用来凑数,令编号和用户输入一致.
}

void AddPersonInfo(){
    printf("*新增联系人*\n");
    if(g_address_book.size>=MAX_PERSON_INFO_SIZE){
        printf("新增联系人失败!\n");
        return;
    }
    PersonInfo* person_info=&g_address_book.person[g_address_book.size];
    printf("请输入联系人姓名:");
    //必须获取到一个指针,修改的内容是一个预期的内容(否则person_info只是一份拷贝,无法修改)
    scanf("%s",person_info->name);
    printf("请输入联系人电话:");
    scanf("%s",person_info->phone);
    printf("请输入联系人性别(male 男,female 女,unknow 未知):");
    scanf("%s",person_info->sex);
    printf("请输入联系人年龄:");
    scanf("%s",person_info->age);
    printf("请输入联系人地址:");
    scanf("%s",person_info->address);
    ++g_address_book.size;
    printf("新增联系人成功!\n");
}

void DelPersonInfo(){//交换要删除的联系人和最后一个联系人,然后执行删除最后一个联系人的操作
    printf("*删除联系人*\n");
    if(g_address_book.size<=0){
        printf("删除失败,通讯录为空!\n");
        return;
    }
    printf("请输入要删除的序号：");
    int id =0;
    scanf("%d",&id);
    if(id<0||id>=g_address_book.size){
        printf("删除失败！序号有误!\n");
        return;
    }
    g_address_book.person[id]=g_address_book.person[g_address_book.size - 1];//结构体之间赋值
    --g_address_book.size;
    printf("删除联系人成功！\n");
}

void FindPersonInfo(){
    printf("*查找联系人*\n");
    if(g_address_book.size<=0){
        printf("通讯录为空,无法查找联系人!\n");
        return;
    }
    printf("请输入要查找的姓名:");
    char name[MAX_DATA_SIZE]={0};
    scanf("%s",name);
    for (int i = 0; i <g_address_book.size ; ++i) {
        PersonInfo* info= &g_address_book.person[i];
        if(strcmp(info->name,name)==0){
            printf("[%d] %s\t%s\n",i,info->name,info->phone);
        }else{
            printf("联系人列表查无此人!\n");
            return;
        }
    }
    printf("查找联系人成功!\n");
}

void UpdatePersonInfo(){
    printf("*更新联系人信息*\n");
    if(g_address_book.size<=0){
        printf("通讯录为空,无法更新联系人!\n");
        return;
    }
    printf("请输入要更新的联系人序号:");
    int id=0;
    scanf("%d",&id);
    if(id<0||id>=g_address_book.size){
        printf("序号有误,修改失败!\n");
        return;
    }
    PersonInfo* info=&g_address_book.person[id];
    printf("旧的姓名为:(%s),请输入新的姓名(若不修改请输入*):\n",info->name);
    char name[MAX_DATA_SIZE]={0};
    scanf("%s",name);
    if(strcmp(name,"*")!=0){
        strcpy(info->name,name);
    }
    char phone[MAX_DATA_SIZE]={0};
    printf("旧的号码为:(%s),请输入新的电话(若不修改请输入*):\n",info->phone);
    scanf("%s",phone);
    if(strcmp(phone,"*")!=0){
        strcpy(info->phone,phone);
    }
    printf("旧的性别为:(%s),请输入新的性别(若不修改请输入*):\n",info->sex);
    char sex[MAX_DATA_SIZE]={0};
    scanf("%s",sex);
    if(strcmp(sex,"*")!=0){
        strcpy(info->sex,sex);
    }
    printf("旧的年龄为:(%s),请输入新的年龄(若不修改请输入*):\n",info->age);
    char age[MAX_DATA_SIZE]={0};
    scanf("%s",age);
    if(strcmp(age,"*")!=0){
        strcpy(info->age,age);
    }
    printf("旧的地址为:(%s),请输入新的地址(若不修改请输入*):\n",info->address);
    char address[MAX_DATA_SIZE]={0};
    scanf("%s",address);
    if(strcmp(address,"*")!=0){
        strcpy(info->address,address);
    }
    printf("成功更新联系人信息!\n");
}

void PrintAllPersonInfo(){
    printf("*打印全部联系人*\n");
    for (int i = 0; i <g_address_book.size ; ++i) {
        PersonInfo* info =&g_address_book.person[i];//结构体变量触发拷贝，要定义一个指针
        printf("[%d]姓名:%s\t电话:%s\t性别:%s\t年龄:%s\t地址:%s\n",
                i,info->name,info->phone,info->sex,info->age,info->address);
    }
    printf("共打印了%d条数据！\n",g_address_book.size);
    printf("打印全部联系人成功！\n");
}

void SortPersonInfo(){//strcmp 姓名字典序
    if(g_address_book.size<=0){
        printf("通讯录为空,无法排序联系人!\n");
        return;
    }
    for (int bound = 0; bound < g_address_book.size ; ++bound) {
        for (int cur = (g_address_book.size)-1; cur >bound ; --cur) {
            PersonInfo* latter=&g_address_book.person[cur];
            PersonInfo* former=&g_address_book.person[cur - 1];
            if(strcmp(latter->name, former->name) < 0){
                ++g_address_book.size;
                g_address_book.person[g_address_book.size-1]=g_address_book.person[cur];
                g_address_book.person[cur]=g_address_book.person[cur-1];
                g_address_book.person[cur-1]=g_address_book.person[g_address_book.size-1];
                --g_address_book.size;
            }
        }
    }
    printf("联系人排序成功!\n");
}

void ClearPersonInfo(){
    printf("*清空联系人*\n");
    if(g_address_book.size<=0){
        printf("通讯录已为空!\n");
        return;
    }
    printf("!-------警告-------!\n");
    printf("您真的要清空所有数据吗???\n");
    printf("是的!(Y) 不是!(N)\n");
    printf("!-------警告-------!\n");
    char choice[1024]={0};
    scanf("%s",choice);
    if(strcmp(choice,"Y")==0){
        g_address_book.size=0;
        printf("成功清除全部联系人数据!\n");
    }else{
        printf("清空操作取消\n");
    }
}

typedef  void(*Func)();

int main(){
    Func arr[]={
            Empty,
            AddPersonInfo,
            DelPersonInfo,
            FindPersonInfo,
            UpdatePersonInfo,
            PrintAllPersonInfo,
            SortPersonInfo,
            ClearPersonInfo
    };

    Init();

    while (1){
        int choice =Menu();
        if(choice<0||choice>= sizeof(arr)/ sizeof(arr[0])){
            printf("您的输入有误!\n");
            continue;
        }
        if(choice==0){
            printf("goodbye!\n");
            break;
        }
        arr[choice]();//借助转移表调用各个函数,转移表:函数指针数组
    }
    return 0;
}

然后遇到了第一个要加入的功能 , 将通讯录的大小改为动态 , 得到了一些提示后发现这并不困难 , 只修改了两个部分的代码 , 就实现了动态通讯录.

typedef struct AddressBook{
    PersonInfo* person;
    int size;
    int capacity;
}AddressBook;

void Init(){
    assert(&g_address_book != NULL);
    g_address_book.size=0;
    g_address_book.capacity=1;
    g_address_book.person=(PersonInfo*)malloc(sizeof(PersonInfo)*g_address_book.capacity);

    for (int i = 0; i <g_address_book.capacity ; ++i) {
        memset(g_address_book.person[i].name,0,MAX_DATA_SIZE);
        memset(g_address_book.person[i].phone,0,MAX_DATA_SIZE);
        memset(g_address_book.person[i].sex,0,MAX_DATA_SIZE);
        memset(g_address_book.person[i].age,0,MAX_DATA_SIZE);
        memset(g_address_book.person[i].address,0,MAX_DATA_SIZE);
    }
}

将原来的person上限1000去掉 , 新增一个容量capacity作为通讯录可容纳的容量 . 然后用malloc函数开辟动态内存空间存储联系人 . 再在后面的新增联系人部分当人数达到上限时的报错功能改为自动扩容即可.
很关键的一点是在扩容时要先将原有的联系人保存下来扩容后再加载回去.

void AddPersonInfo(){
    assert(&g_address_book != NULL);
    printf("*新增联系人*\n");
    if(g_address_book.size>=g_address_book.capacity){
        //扩容
        printf("扩容中...\n");
        g_address_book.capacity+=10;

        //先将结构体中的联系人保存到文件再进行释放
        printf("*保存联系人*\n");
        FILE* fp=fopen("d:/test.txt","w");
        for (int i = 0; i <g_address_book.size ; ++i) {
            fwrite(g_address_book.person,1, sizeof(PersonInfo),fp);
        }
        free(g_address_book.person);
        g_address_book.person=NULL;
        printf("保存联系人成功!\n");

        free(g_address_book.person);
        g_address_book.person=(PersonInfo*)malloc(sizeof(PersonInfo)*g_address_book.capacity);
        printf("扩容成功!\n");

        FILE* fp1=fopen("D:/test.txt","r");
        if(fp1==NULL){
            perror("读取联系人结果:\n");
            return;
        }
        PersonInfo tmp={0};
        int count=0;
        while(fread(&tmp,1, sizeof(PersonInfo),fp1)){
            ++count;
            printf("正在读取第%d条联系人信息...\n",count);
            g_address_book.capacity+=10;
            free(g_address_book.person);
            g_address_book.person=(PersonInfo*)malloc(sizeof(PersonInfo)*g_address_book.capacity);

            g_address_book.person[g_address_book.size]=tmp;
            ++g_address_book.size;
        }
        fclose(fp1);
        fp1=NULL;
        printf("读取联系人成功!\n");

    }

然后保存联系人功能合并到退出当中,退出时保存联系人,直接关闭程序则无法保存联系人

完整代码:

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

//#define MAX_PERSON_INFO_SIZE 1000
#define MAX_DATA_SIZE 1024

typedef struct PersonInfo{
    char name[MAX_DATA_SIZE];
    char phone[MAX_DATA_SIZE];
    char sex[MAX_DATA_SIZE];
    char age[MAX_DATA_SIZE];
    char address[MAX_DATA_SIZE];
}PersonInfo;

typedef struct AddressBook{
    PersonInfo* person;
    int size;
    int capacity;
}AddressBook;

AddressBook g_address_book;//g表示全局变量


void Init(){
    g_address_book.size=0;
    g_address_book.capacity=1;
    g_address_book.person=(PersonInfo*)malloc(sizeof(PersonInfo)*g_address_book.capacity);

    for (int i = 0; i <g_address_book.capacity ; ++i) {
        memset(g_address_book.person[i].name,0,MAX_DATA_SIZE);
        memset(g_address_book.person[i].phone,0,MAX_DATA_SIZE);
        memset(g_address_book.person[i].sex,0,MAX_DATA_SIZE);
        memset(g_address_book.person[i].age,0,MAX_DATA_SIZE);
        memset(g_address_book.person[i].address,0,MAX_DATA_SIZE);
    }
}

int Menu(){
    printf("==========================\n");
    printf("1.新增联系人\n");
    printf("2.删除联系人\n");
    printf("3.查找联系人\n");
    printf("4.更新联系人信息\n");
    printf("5.打印全部联系人\n");
    printf("6.排序联系人\n");
    printf("7.清空联系人\n");
    printf("0.保存联系人并退出\n");
    printf("==========================\n");
    printf("请输入您的选择:");
    int choice=0;
    scanf("%d",&choice);
    return choice;
}


void Empty(){
    //这个函数用来凑数,令编号和用户输入一致.
}

void AddPersonInfo(){
    assert(&g_address_book != NULL);
    printf("*新增联系人*\n");
    if(g_address_book.size>=g_address_book.capacity){
        //扩容
        printf("扩容中...\n");
        g_address_book.capacity+=10;

        //先将结构体中的联系人保存到文件再进行释放
        printf("*保存联系人*\n");
        FILE* fp=fopen("d:/test.txt","w");
        for (int i = 0; i <g_address_book.size ; ++i) {
            fwrite(g_address_book.person,1, sizeof(PersonInfo),fp);
        }
        free(g_address_book.person);
        g_address_book.person=NULL;
        printf("保存联系人成功!\n");

        free(g_address_book.person);
        g_address_book.person=(PersonInfo*)malloc(sizeof(PersonInfo)*g_address_book.capacity);
        printf("扩容成功!\n");

        FILE* fp1=fopen("D:/test.txt","r");
        if(fp1==NULL){
            perror("读取联系人结果:\n");
            return;
        }
        PersonInfo tmp={0};
        int count=0;
        while(fread(&tmp,1, sizeof(PersonInfo),fp1)){
            ++count;
            printf("正在读取第%d条联系人信息...\n",count);
            g_address_book.capacity+=10;
            free(g_address_book.person);
            g_address_book.person=(PersonInfo*)malloc(sizeof(PersonInfo)*g_address_book.capacity);

            g_address_book.person[g_address_book.size]=tmp;
            ++g_address_book.size;
        }
        fclose(fp1);
        fp1=NULL;
        printf("读取联系人成功!\n");

    }
    PersonInfo* person_info=&g_address_book.person[g_address_book.size];
    printf("请输入联系人姓名:");
    //必须获取到一个指针,修改的内容是一个预期的内容(否则person_info只是一份拷贝,无法修改)
    scanf("%s",person_info->name);
    printf("请输入联系人电话:");
    scanf("%s",person_info->phone);
    printf("请输入联系人性别(male 男,female 女,unknow 未知):");
    scanf("%s",person_info->sex);
    printf("请输入联系人年龄:");
    scanf("%s",person_info->age);
    printf("请输入联系人地址:");
    scanf("%s",person_info->address);
    ++g_address_book.size;

    printf("新增联系人成功!\n");
}

void DelPersonInfo(){//交换要删除的联系人和最后一个联系人,然后执行删除最后一个联系人的操作
    assert(&g_address_book != NULL);
    printf("*删除联系人*\n");
    if(g_address_book.size<=0){
        printf("删除失败,通讯录为空!\n");
        return;
    }
    printf("请输入要删除的序号：");
    int id =0;
    scanf("%d",&id);
    if(id<0||id>=g_address_book.size){
        printf("删除失败！序号有误!\n");
        return;
    }
    g_address_book.person[id]=g_address_book.person[g_address_book.size - 1];//结构体之间赋值
    --g_address_book.size;
    printf("删除联系人成功！\n");
}

void FindPersonInfo(){
    assert(&g_address_book != NULL);
    printf("*查找联系人*\n");
    if(g_address_book.size<=0){
        printf("通讯录为空,无法查找联系人!\n");
        return;
    }
    printf("请输入要查找的姓名:");
    char name[MAX_DATA_SIZE]={0};
    scanf("%s",name);
    for (int i = 0; i <g_address_book.size ; ++i) {
        PersonInfo* info= &g_address_book.person[i];
        if(strcmp(info->name,name)==0){
            printf("[%d] %s\t%s\n",i,info->name,info->phone);
        }else{
            printf("联系人列表查无此人!\n");
            return;
        }
    }
    printf("查找联系人成功!\n");
}

void UpdatePersonInfo(){
    assert(&g_address_book != NULL);
    printf("*更新联系人信息*\n");
    if(g_address_book.size<=0){
        printf("通讯录为空,无法更新联系人!\n");
        return;
    }
    printf("请输入要更新的联系人序号:");
    int id=0;
    scanf("%d",&id);
    if(id<0||id>=g_address_book.size){
        printf("序号有误,修改失败!\n");
        return;
    }
    PersonInfo* info=&g_address_book.person[id];
    printf("旧的姓名为:(%s),请输入新的姓名(若不修改请输入*):\n",info->name);
    char name[MAX_DATA_SIZE]={0};
    scanf("%s",name);
    if(strcmp(name,"*")!=0){
        strcpy(info->name,name);
    }
    char phone[MAX_DATA_SIZE]={0};
    printf("旧的号码为:(%s),请输入新的电话(若不修改请输入*):\n",info->phone);
    scanf("%s",phone);
    if(strcmp(phone,"*")!=0){
        strcpy(info->phone,phone);
    }
    printf("旧的性别为:(%s),请输入新的性别(若不修改请输入*):\n",info->sex);
    char sex[MAX_DATA_SIZE]={0};
    scanf("%s",sex);
    if(strcmp(sex,"*")!=0){
        strcpy(info->sex,sex);
    }
    printf("旧的年龄为:(%s),请输入新的年龄(若不修改请输入*):\n",info->age);
    char age[MAX_DATA_SIZE]={0};
    scanf("%s",age);
    if(strcmp(age,"*")!=0){
        strcpy(info->age,age);
    }
    printf("旧的地址为:(%s),请输入新的地址(若不修改请输入*):\n",info->address);
    char address[MAX_DATA_SIZE]={0};
    scanf("%s",address);
    if(strcmp(address,"*")!=0){
        strcpy(info->address,address);
    }
    printf("成功更新联系人信息!\n");
}

void PrintAllPersonInfo(){
    assert(&g_address_book != NULL);
    printf("*打印全部联系人*\n");
    for (int i = 0; i <g_address_book.size ; ++i) {
        PersonInfo* info =&g_address_book.person[i];//结构体变量触发拷贝，要定义一个指针
        printf("[%d]姓名:%s 电话:%s 性别:%s 年龄:%s 地址:%s\n",
               i,info->name,info->phone,info->sex,info->age,info->address);
    }
    printf("共打印了%d条数据！\n",g_address_book.size);
    printf("打印全部联系人成功！\n");
}

void SortPersonInfo(){//strcmp 姓名字典序
    assert(&g_address_book != NULL);
    if(g_address_book.size<=0){
        printf("通讯录为空,无法排序联系人!\n");
        return;
    }
    for (int bound = 0; bound < g_address_book.size ; ++bound) {
        for (int cur = (g_address_book.size)-1; cur >bound ; --cur) {
            PersonInfo* latter=&g_address_book.person[cur];
            PersonInfo* former=&g_address_book.person[cur - 1];
            if(strcmp(latter->name, former->name) < 0){
                ++g_address_book.size;
                g_address_book.person[g_address_book.size-1]=g_address_book.person[cur];
                g_address_book.person[cur]=g_address_book.person[cur-1];
                g_address_book.person[cur-1]=g_address_book.person[g_address_book.size-1];
                --g_address_book.size;
            }
        }
    }
    printf("联系人排序成功!\n");
}

void ClearPersonInfo(){
    assert(&g_address_book != NULL);
    printf("*清空联系人*\n");
    if(g_address_book.size<=0){
        printf("通讯录已为空!\n");
        return;
    }
    printf("!-------警告-------!\n");
    printf("您真的要清空所有数据吗???\n");
    printf("是的!(Y) 不是!(N)\n");
    printf("!-------警告-------!\n");
    char choice[1024]={0};
    scanf("%s",choice);
    if(strcmp(choice,"Y")==0){
        g_address_book.size=0;
        printf("成功清除全部联系人数据!\n");
    }else{
        printf("清空操作取消\n");
    }
}

void ReadPersonInfo(){
    FILE* fp=fopen("D:/test.txt","r");
    if(fp==NULL){
        perror("读取联系人结果:\n");
        return;
    }
    PersonInfo tmp={0};
    int count=0;
    while(fread(&tmp,1, sizeof(PersonInfo),fp)){
        ++count;
        printf("正在读取第%d条联系人信息...\n",count);
        g_address_book.capacity+=10;
        free(g_address_book.person);
        g_address_book.person=(PersonInfo*)malloc(sizeof(PersonInfo)*g_address_book.capacity);

        g_address_book.person[g_address_book.size]=tmp;
        ++g_address_book.size;
    }
    fclose(fp);
    fp=NULL;
    printf("读取联系人成功!\n");
}

void SavePersonInfo(){
    assert(&g_address_book != NULL);
    printf("*保存联系人*\n");
    FILE* fp=fopen("d:/test.txt","w");
    for (int i = 0; i <g_address_book.size ; ++i) {
        fwrite(g_address_book.person,1, sizeof(PersonInfo),fp);
    }
    free(g_address_book.person);
    g_address_book.person=NULL;
    printf("保存联系人成功!\n");
}

typedef  void(*Func)();

int main(){
    Func arr[]={
            Empty,
            AddPersonInfo,
            DelPersonInfo,
            FindPersonInfo,
            UpdatePersonInfo,
            PrintAllPersonInfo,
            SortPersonInfo,
            ClearPersonInfo,
    };

    Init();
    printf("读取联系人\n");
    ReadPersonInfo();

    while (1){
        int choice =Menu();
        if(choice<0||choice>= sizeof(arr)/ sizeof(arr[0])){
            printf("您的输入有误!\n");
            continue;
        }
        if(choice==0){
            if(g_address_book.size<=0){
                SavePersonInfo();
                printf("通讯录已为空无需保存!\n");
                printf("goodbye!\n");
                break;
            }else{
                SavePersonInfo();
                printf("goodbye!\n");
                break;
            }
        }
        arr[choice]();//借助转移表调用各个函数,转移表:函数指针数组
    }
    return 0;
}