c - 程序因 fclose 而崩溃

Question

我正在使用以下文本文件:https://mega.nz/#!EN4iRJxA!VtKFEl9dlQHWHIzcgfOfpXTt9_ill_YkgsLWL3nORLg 以及以下代码:

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

    typedef struct
    {
        int id;
        char lastname[25];
        char name[20];
        float average;
    }student;

    int main(){
        int i;
        student *pointer= (student*) malloc(3);

        FILE *file= fopen("Struct.txt", "r");
        fread(pointer, sizeof(student), 3, file);
        for(i= 0; i< 3; i++){
            printf("Id: %d\nName: %s\nLast name: %s\nAverage: %.2f\n",
                (pointer+ i) -> id,
                (pointer+ i) -> name,
                (pointer+ i) -> lastname,
                (pointer+ i) -> average);
        }
        fclose(file);
        system("pause");
        return 0;   
    }

当我删除 fclose 函数时它起作用了，但我检查了一下它似乎是正确的。我错过了什么？

Answer 1

这与您的fclose 无关，相反您需要解决两件事:

• 需要检查fopen的返回错误:

  if( NULL == file )
  {
      printf( "Cannot open\n" );
      exit( 1 );
  }
  

• 您的 malloc 代码看起来不正确，应该是: student *pointer= malloc(3 * sizeof(student));