c - 嵌套结构分配内存

Question

我有2个结构:

第一个:

 struct Link
    {
        frame_t *frame;
        struct Link *next;
    };

    typedef struct Link link_t;

第二个:

struct Frame
{
    char            *name;
    unsigned int    duration;
    char            *path;  // may change to FILE*
};

typedef struct Frame frame_t;

我尝试使用函数为 Link 结构分配内存，但它不起作用。

调用函数:

link_t* list = NULL;
    list = AddItemToList(list);

这就是函数:

link_t* AddItemToList(link_t* item)
{
    if (item == NULL)
    {
        item = (link_t*)calloc(1, sizeof(link_t) );

        item->frame = (frame_t*)calloc(1, sizeof(frame_t));


        printf("Please insert frame path: ");
        scanf("%s", item->frame->path);

        printf("Please insert frame duration(in miliseconds): ");
        scanf("%d", item->frame->duration);

        printf("Please choose a name for that frame: ");
        scanf("%s", item->frame->name);
    }
    else item->next = AddItemToList(item-> next);
    return item;
}

Answer 1

您从未在 Link 结构中分配名称或路径。您正在扫描未初始化的内存。

item->frame = (frame_t*)calloc(1, sizeof(frame_t));

// You need to add something like:
item->frame->name = (char *)calloc(1, some_string_size);
item->frame->path = (char *)calloc(1, some_string_size);