Struct 将结构从文件返回到结构数组时出现问题

当我通过调试检查函数时，该函数工作正常，但在函数完成后，数组为空

这是结构：

typedef struct coordinates  
{
int x_l;
int y_l;
int x_r;
int y_r;
} Coordinates;

typedef struct field 
{
int Id;
Coordinates location;
int area;
int price;
} Field;

这就是功能：

    int ReadFromFile(Field *pArr)
{
    int size;
    int i;


 FILE *f = fopen("c:\\migrashim\\migrashim.txt", "r");

 if (f == NULL)
    {
        printf("error open file");
        exit (1);
    }
fseek(f,0,SEEK_SET);    
fscanf(f, "%d\n", &size);

pArr=(Field*)realloc(pArr,sizeof(Field)*(size));


for (i=0 ; i<size ; i++)
{
    fscanf(f, "%d\n", &pArr[i].Id);
    fscanf(f, "%d %d\n", &pArr[i].location.x_l,&pArr[i].location.y_l);
    fscanf(f, "%d %d\n", &pArr[i].location.x_r,&pArr[i].location.y_r);
}

    return size;
    }

---

tnx伙计们…

您正在将指针传递到ReadFromFile并调整大小

realloc将尝试就地调整大小，但如果不能，它将分配一个新块，复制现有数据，然后释放旧块

您的函数没有考虑到块可能已经移动（您没有返回realloc返回的指针）

编辑：

代码应该如下所示：

int ReadFromFile(Field **pArr)
{
    int size;
    int i;

    FILE *f = fopen("c:\\migrashim\\migrashim.txt", "r");

    if (f == NULL)
    {
        printf("error open file");
        exit (1);
    }

    fscanf(f, "%d\n", &size);

    *pArr = (Field*)realloc(*pArr, sizeof(Field)* size);

    for (i = 0; i < size; i++)
    {
        fscanf(f, "%d\n", &(*pArr)[i].Id);
        fscanf(f, "%d %d\n", &(*pArr)[i].location.x_l, &(*pArr)[i].location.y_l);
        fscanf(f, "%d %d\n", &(*pArr)[i].location.x_r, &(*pArr)[i].location.y_r);
    }

    fclose(f);

    return size;
}

---

你能举个例子吗。。？

int ReadFromFile(Field **pArr)
{
    int size;
    int i;

    FILE *f = fopen("c:\\migrashim\\migrashim.txt", "r");

    if (f == NULL)
    {
        printf("error open file");
        exit (1);
    }

    fscanf(f, "%d\n", &size);

    *pArr = (Field*)realloc(*pArr, sizeof(Field)* size);

    for (i = 0; i < size; i++)
    {
        fscanf(f, "%d\n", &(*pArr)[i].Id);
        fscanf(f, "%d %d\n", &(*pArr)[i].location.x_l, &(*pArr)[i].location.y_l);
        fscanf(f, "%d %d\n", &(*pArr)[i].location.x_r, &(*pArr)[i].location.y_r);
    }

    fclose(f);

    return size;
}

{
    counter_2 = ReadFromFile(&pFieldArr);
    printf("\nFile loaded successfully!");
    New_Field_flag = 0;
    Exit = 0;
    break;
}