将数据添加到来自文件的双向链表

Question

就我目前的功能而言，我只能从文件中读取第一组数据。我确信这是因为 !feof 没有按照我想要的方式运行，但也可能是由于打印列表功能错误造成的，但我不确定。我对使用动态内存非常陌生，所以请耐心等待。

从文件加载

void load(FILE *file, Node *head)
{
    char tempArtist[30] = {'\0'}, tempAlbum[30] = {'\0'}, tempTitle[30] = {'\0'}, tempGenre[30] = {'\0'}, tempSpace = '\0';
    SongLength *tempLength = NULL;
    char tempPlay[100] = {'\0'}, tempRating[6] = {'\0'}, tempMins[3] = {'\0'}, tempSecs[3] = {'\0'};

    tempLength = (SongLength *)malloc(sizeof(SongLength));

    while (!feof(file))
    {
        while (head->pNext == NULL) // Here is where I need to shift to the next node
        {
            fscanf(file, "%s", &tempArtist);
            fscanf(file, "%c", &tempSpace);

            strcpy(tempLength->mins, tempMins);
            strcpy(tempLength->secs, tempSecs);
            strcpy(head->data->artist, tempArtist);
            strcpy(head->data->length->mins, tempLength->mins);
            strcpy(head->data->length->secs, tempLength->secs);

            insertNode(head, head->data);
        }
    }
    free(tempLength);
}

插入链表

void insertNode(Node *head, Record *data)
{
    while(head->pNext == NULL)
    {
        head=head->pNext;
    }

    head->pNext=(Node*)malloc(sizeof(Node));
    head->pNext->data = (Record*)malloc(sizeof(Record));
    head->pNext->data->length=(SongLength*)malloc(sizeof(SongLength));

    (head->pNext)->pPrev=head;
    head=head->pNext;
    head->data=data;
    head->pNext=NULL;

}

打印列表中的所有数据（希望如此）

void display (Node *head)
{

    while (head->pNext != NULL)
    {
        printf ("Artist: %s\n", head->data->artist);
        printf ("Length(mm:ss) %s:%s\n", head->data->length->mins,head->data->length->secs);

        head=head->pNext;
    }
    putchar ('\n');
}

我已经删除了 fscanf() 和 printf() 中的一个，以减少代码。

结构

typedef struct songlength
{
    char mins[3];
    char secs[3];
}SongLength;

typedef struct record
{
    char artist[30];
    struct songlength *length;      
}Record;

typedef struct node
{
    struct node *pPrev;
    struct record *data;
    struct node *pNext;
}Node;

Answer 1

函数调用insertNode(head,head->data); 看起来很奇怪。第二个参数必须是不是来自 head 的数据，否则 head 中的数据将被重写以获取任何新记录。

所以在load函数内部为Record分配内存，不要使用head->data。