IT工单系统新增工单覆盖旧数据问题求助（附C语言代码）

旧工单数据被覆盖的核心原因是**createTicket函数中使用栈上的局部字符数组存储用户输入，然后直接把数组地址赋值给Ticket结构体的指针成员**。栈内存在函数执行完毕后会被回收复用，每次调用createTicket时，这些局部数组的内存位置重复，新输入会覆盖旧内容，导致所有Ticket结构体的字符串指针都指向同一块栈内存，最终显示的都是最后一次输入的数据。

为每个字符串成员动态分配堆内存（用malloc+strcpy），确保每个工单的字符串数据存储在独立内存中，不会被覆盖。同时补充内存释放逻辑，避免内存泄漏。

修改后的核心函数 #

1. 修复createTicket函数 #

#include <string.h> // 需新增头文件，用于strlen和strcpy

Ticket* createTicket() {
    Ticket* newTicket = (Ticket*)malloc(sizeof(Ticket));
    if (newTicket == NULL) {
        printf("Memory allocation failed\n");
        exit(1);
    }

    char email[120];
    char name[120];
    char date[480];
    char issue[480];
    int num = 0;

    // 姓名：读取后动态分配内存并复制内容
    printf("What's the name: ");
    scanf("%s", name); // 数组名本身是地址，无需&
    newTicket->name = malloc(strlen(name) + 1); // +1存储字符串终止符
    if (newTicket->name == NULL) {
        printf("Memory allocation failed for name\n");
        exit(1);
    }
    strcpy(newTicket->name, name);

    // 邮箱
    printf("What's the email: ");
    scanf("%s", email);
    newTicket->email = malloc(strlen(email) + 1);
    if (newTicket->email == NULL) {
        printf("Memory allocation failed for email\n");
        exit(1);
    }
    strcpy(newTicket->email, email);

    // 日期
    printf("What's the date: ");
    scanf("%s", date);
    newTicket->date = malloc(strlen(date) + 1);
    if (newTicket->date == NULL) {
        printf("Memory allocation failed for date\n");
        exit(1);
    }
    strcpy(newTicket->date, date);

    // 优先级（原逻辑保留）
    while (num > 5 || num < 1) {
        printf("What's the priority of the issue (1-5): ");
        scanf("%d", &num);
        if (num > 5 || num < 1) {
            printf("Invalid input. Enter a number between 1 and 5\n");
        } else {
            newTicket->priority = num;
        }
    }

    // 问题描述
    printf("What's the issue? (maximum characters: 120): ");
    scanf("%s", issue);
    newTicket->issue_description = malloc(strlen(issue) + 1);
    if (newTicket->issue_description == NULL) {
        printf("Memory allocation failed for issue description\n");
        exit(1);
    }
    strcpy(newTicket->issue_description, issue);

    newTicket->is_closed = 0;
    newTicket->issue_solution = "None"; // 字符串字面量无需动态分配
    newTicket->next = NULL;
    return newTicket;
}

2. 补充内存释放逻辑 #

原代码仅释放Ticket结构体本身，需新增字符串成员的释放：

// 在main函数的内存释放部分修改
Ticket* temp;
while (head != NULL) {
    temp = head;
    head = head->next;
    // 先释放字符串成员
    free(temp->name);
    free(temp->email);
    free(temp->date);
    free(temp->issue_description);
    // issue_solution是字符串字面量，无需free
    free(temp); // 最后释放结构体本身
}

完整修复代码 #

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

typedef struct ticket {
    char *name;
    char *email;
    char *date;
    int priority;
    char *issue_description;
    int is_closed;
    char *issue_solution;
    struct ticket* next;
}Ticket;

Ticket* createTicket() {
    Ticket* newTicket = (Ticket*)malloc(sizeof(Ticket));
    if (newTicket == NULL) {
        printf("Memory allocation failed\n");
        exit(1);
    }

    char email[120];
    char name[120];
    char date[480];
    char issue[480];
    int num = 0;

    printf("What's the name: ");
    scanf("%s", name);
    newTicket->name = malloc(strlen(name) + 1);
    if (newTicket->name == NULL) {
        printf("Memory allocation failed for name\n");
        exit(1);
    }
    strcpy(newTicket->name, name);

    printf("What's the email: ");
    scanf("%s", email);
    newTicket->email = malloc(strlen(email) + 1);
    if (newTicket->email == NULL) {
        printf("Memory allocation failed for email\n");
        exit(1);
    }
    strcpy(newTicket->email, email);

    printf("What's the date: ");
    scanf("%s", date);
    newTicket->date = malloc(strlen(date) + 1);
    if (newTicket->date == NULL) {
        printf("Memory allocation failed for date\n");
        exit(1);
    }
    strcpy(newTicket->date, date);

    while (num > 5 || num < 1) {
        printf("What's the priority of the issue (1-5): ");
        scanf("%d", &num);
        if (num > 5 || num < 1) {
            printf("Invalid input. Enter a number between 1 and 5\n");
        } else {
            newTicket->priority = num;
        }
    }

    printf("What's the issue? (maximum characters: 120): ");
    scanf("%s", issue);
    newTicket->issue_description = malloc(strlen(issue) + 1);
    if (newTicket->issue_description == NULL) {
        printf("Memory allocation failed for issue description\n");
        exit(1);
    }
    strcpy(newTicket->issue_description, issue);

    newTicket->is_closed = 0;
    newTicket->issue_solution = "None";
    newTicket->next = NULL;
    return newTicket;
}

void addTicketAtEnd(Ticket** head, Ticket* newTicket) {
    if (*head == NULL) {
        *head = newTicket;
        return;
    }
    Ticket* temp = *head;
    while (temp->next != NULL) {
        temp = temp->next;
    }
    temp->next = newTicket;
}

void printList(Ticket* head) {
    if (head == NULL) {
        printf("The list is empty.\n");
        return;
    }
    printf("Ticket List:\n");
    Ticket* temp = head;
    while (temp != NULL) {
        printf("Name: %s\n", temp->name);
        printf("Email: %s\n", temp->email);
        printf("Date: %s\n", temp->date);
        printf("Priority: %d\n", temp->priority);
        printf("Issue: %s\n", temp->issue_description);
        printf("Solution: %s\n", temp->issue_solution);
        printf("-------------------------\n");
        temp = temp->next;
    }
}

Ticket* insertTicket(Ticket* head) {
    Ticket* newTicket = createTicket();
    Ticket* temp = head;

    if(head == NULL){
        return newTicket;
    }

    if (head->priority <= newTicket->priority){
        newTicket->next = head;
        return newTicket;
    } else {
        while(1){
            if (temp->next == NULL){
                addTicketAtEnd(&head, newTicket);
                return head;
            }else if(temp->next->priority <= newTicket->priority){
                newTicket->next = temp->next;
                temp->next = newTicket;
                return head;
            } else {
                temp = temp->next;
            }
        }
    }
}

int main() {
    Ticket* head = NULL;
    int option = 1;

    while (1){
        if (option == 1){
            head = insertTicket(head);
        } else if (option == 2) {
            // 后续可实现关闭工单逻辑
        } else if (option == 3){
            printList(head);
        } else if (option == 4){
            break;
        }
        while (1){
            printf("Enter a value between 1-4. 1. Add a ticket. 2. resolve a ticket. 3. print all tickets. 4. Exit: ");
            scanf("%d", &option);
            if(option > 4 || option < 1){
                printf("Invalid input. Enter a number between 1 and 4\n");
            } else {
                break;
            }
        }
    }

    Ticket* temp;
    while (head != NULL) {
        temp = head;
        head = head->next;
        free(temp->name);
        free(temp->email);
        free(temp->date);
        free(temp->issue_description);
        free(temp);
    }
    return 0;
}

内容的提问来源于stack exchange，提问作者Griffin Zee