C - 如何通过引用将结构指针数组传递给函数

Question

我有这个结构:

typedef struct {
    char name[31];
    int played;
    int won;
    int lost;
    int tie;
    int points;
} Player;

这个函数用文件中的数据填充结构数组:

int load(Player *players[], int max_players, int *player_count)
{
    static const char filename[] = "players.txt";
    FILE *file = fopen(filename, "r");

    if (file != NULL)
    {
        char line[128]; 

        players = malloc(max_players * sizeof *players);

        while (1) /* read until end of file */
        {

            players[*player_count] = malloc(sizeof(Player));

            if (*player_count < max_players && fgets(players[*player_count]->name, sizeof players[*player_count]->name, file) != NULL)
            {
                fscanf(file, "%d", &players[*player_count]->played);    // read played
                fscanf(file, "%d", &players[*player_count]->won);       // read won 
                fscanf(file, "%d", &players[*player_count]->lost);      // read lost 
                fscanf(file, "%d", &players[*player_count]->tie);       // read tie 
                fscanf(file, "%d", &players[*player_count]->points);    // read points 
                fgets(line, sizeof line, file);                         // read new line

                // increase player count
                *player_count += 1;
            }
            else
            {
                break;
            }
        }

        fclose(file);
    }
    else
    {
        return 0;
    }
    return 1;
}

现在我在通过传递玩家作为引用来调用它时遇到问题，这样玩家的更新数据就会反射(reflect)在调用端。

下面是我的调用代码，我认为有问题:

Player *players[MAX_PLAYERS] = { NULL };
int playerCount = 0;
load(players, MAX_PLAYERS, &playerCount);

当我调试代码时，函数中填充了玩家的数组，但当它返回时，玩家的值仍然为空。

如有任何帮助，我们将不胜感激。

Answer 1

您正在覆盖局部变量 players。

从您不需要的函数中删除以下行。

   players = malloc(max_players * sizeof *players);|

因为您已经在 main 中有了指针数组。

---

你不需要Player类型的指针数组你只需要Player类型的数组

Player *players;
load(&players, MAX_PLAYERS, &playerCount);

并且在load函数中。

int load(Player **players, int max_players, int *player_count)
{
    static const char filename[] = "players.txt";
    FILE *file = fopen(filename, "r");

    if (file != NULL)
    {
        char line[128]; 

        (*players) = malloc(max_players * sizeof **players);

        while (1) /* read until end of file */
        {


            if (*player_count < max_players && fgets((*players)[*player_count].name, sizeof (*players)[*player_count].name, file) != NULL)
            {
                fscanf(file, "%d", &(*players)[*player_count].played);    // read played
                fscanf(file, "%d", &(*players)[*player_count].won);       // read won 
                fscanf(file, "%d", &(*players)[*player_count].lost);      // read lost 
                fscanf(file, "%d", &(*players)[*player_count].tie);       // read tie 
                fscanf(file, "%d", &(*players)[*player_count].points);    // read points 
                fgets(line, sizeof line, file);                         // read new line

                // increase player count
                *player_count += 1;
            }
            else
            {
                break;
            }
        }

        fclose(file);
    }
    else
    {
        return 0;
    }
    return 1;
}