c - 调试断言失败(文件名!= nullptr)

Question

我是初学者，正在尝试图书馆管理系统，结果出现错误(Debug Assertion Failed)，表达式为(file_name != nullptr ).

当我在主菜单中选择第一个选项时，出现此错误，因此我需要帮助，谢谢:

#include<stdio.h>
#include<stdlib.h>
#include<ctype.h>
#include<string.h>
#define _CRT_SECURE_NO_WARNING

int AddNewBook(librecord);
int Exit();

struct
{
   int id;
   char title;
   char edition;
   int year;
   char location;
   char price;
   int status;
}book;

FILE *librecord;

char book_id;
char book_title;
char book_edition;
char book_year;
char book_location;
char book_price;

char confirmation;
int no_value;

int main(void)
{
   printf("   **         ***          ***     **********   \n");
   printf("   **         ****        ****     **********   \n");
   printf("   **         ** **      ** **     ***          \n");
   printf("   **         **  **    **  **     **********   \n");
   printf("   **         **   **  **   **            ***   \n");
   printf("   *******    **    ****    **     **********   \n");
   printf("   *******    **     **     **     **********   \n");
   printf("\n");
   printf(" Welcome to Library Management System \n");
   printf("\n");
   printf(" MAIN MENU \n");
   printf("\n");
   printf(" 1. Add New Book \n");
   printf(" 2. Edit Book Information \n");
   printf(" 3. Delete Book \n");
   printf(" 4. View Book List \n");
   printf(" 5. Book Check-In \n");
   printf(" 6. Book Check-Out \n");
   printf(" 7. Search \n");
   printf(" 8. Exit \n");

   int choice;
   printf("\n Please enter a number: ");
   scanf_s("%d", &choice);

   switch(choice)
   {
     case 1: 
        system("cls");
        AddNewBook(librecord);
        break;

     case 8: 
        Exit();
     default:
        printf("Wrong Input !!! Please re-enter a number!!! \n");
        system("pause");
        system("cls");
        main();
   }

}

int AddNewBook(FILE *librecord)
{
   librecord = fopen(librecord, "ab+");

   printf("\n");
   printf(" ADD NEW BOOK \n");
   printf("\n");

   printf(" Book ID: ");
   scanf_s(" %d", &book.id);
   fflush(stdin);
   strcpy(book.id, book_id);

   printf("\n Title: ");
   scanf_s(" %s", &book.title);
   fflush(stdin);
   strcpy(book.title, book_title);

   printf("\n Edition: ");
   scanf_s(" %s", &book.edition);
   fflush(stdin);
   strcpy(book.edition, book_edition);

   printf("\n Year of Publication: ");
   scanf_s(" %d", &book.year);
   fflush(stdin);
   strcpy(book.year, book_year);

   printf("\n Shelf Location: ");
   scanf_s(" %s", &book.location);
   fflush(stdin);
   strcpy(book.location, book_location);

   printf("\n Price(RM): ");
   scanf_s(" %s", &book.price);
   fflush(stdin);
   strcpy(book.price, book_price);

   printf("Confirm? (Y/N) \n");
   scanf("%c", &confirmation);
}

int Exit()
{
   exit(0);
}

Debug Assertion Failed!

Program: ...ments\Visual Studio 2015\Projects\Project9\Debug\Project9.exe File: minkernel\crts\ucrt\src\appcrt\stdio\fopen.cpp Line: 30

Expression: file_name != nullptr

For information on how your program can cause an assertion failure, see the Visual C++ documentation on asserts.

(Press Retry to debug the application)

Answer 1

该消息告诉您已将 NULL 文件名传递给 fopen。事实上，librecord 是一个未初始化的静态变量，其初始值为 NULL。 (断言是对编程错误的测试；您不应该将 NULL 作为文件名传递。)

使用合适的文件名初始化 librecord 或在打开文件之前在程序执行期间分配文件名。 (打开文件后，检查是否成功。你不能依赖你的 dta 基础文件实际存在和可读。)