c++ - Libspotify简单的Hello World

我最近开始使用libspotify，并根据jukebox.h的示例代码编写了一个简单的hello世界。

我的代码当前如下所示：

#include <stdio.h>
#include "libspotify/api.h"
#include "Key.h"
#include "Password.h"
#include <stdlib.h>
#include <pthread.h>
#include <time.h>

#define true 1
#define false 0

sp_session *g_session;
bool g_notify_do;
static pthread_mutex_t g_notify_mutex;
static pthread_cond_t g_notify_cond;

#define DEBUG 1

__stdcall static void debug(const char *format, ...) {
    if (!DEBUG)
        return;

    va_list argptr;
    va_start(argptr, format);
    vprintf(format, argptr);
    printf("\n");
}

void assertSpotify(sp_error error, char *details) {
    if (error != SP_ERROR_OK) {
        debug("Fatal error: %s", details);
        exit(1);
    }
}

__stdcall static void notify_main_thread(sp_session *sess) {
    pthread_mutex_lock(&g_notify_mutex);
    g_notify_do = 1;
    pthread_cond_signal(&g_notify_cond);
    pthread_mutex_unlock(&g_notify_mutex);
}

__stdcall static void logged_in(sp_session *sess, sp_error error) {
    assertSpotify(error, "Could not log in.");

    sp_playlistcontainer *pc = sp_session_playlistcontainer(sess);
    printf("Looking at %d playlists\n", sp_playlistcontainer_num_playlists(pc));
}

int main(void) {
    sp_error err;
    static sp_session_callbacks session_callbacks = {};
    static sp_session_config spconfig = {};
    int next_timeout = 0;

    printf("Starting up...\n");
    session_callbacks.notify_main_thread = &notify_main_thread;
    session_callbacks.logged_in = &logged_in;

    spconfig.api_version = SPOTIFY_API_VERSION;
    spconfig.cache_location = "tmp";
    spconfig.settings_location = "tmp";
    spconfig.application_key = g_appkey;
    spconfig.application_key_size = g_appkey_size;
    spconfig.user_agent = "Hello-World";
    spconfig.callbacks = &session_callbacks;

    pthread_mutex_init(&g_notify_mutex, NULL);
    pthread_cond_init(&g_notify_cond, NULL);

    err = sp_session_create(&spconfig, &g_session);
    assertSpotify(err, "Could not create Spotify Session.");
    debug("Session created.");

    err = sp_session_login(g_session, spotify_user, spotify_pw, 0, NULL); //Defined in Password.h
    assertSpotify(err, "Could not log in.");
    debug("Username: %s", sp_session_user_name(g_session));
    err = sp_session_set_connection_type(g_session, SP_CONNECTION_TYPE_WIRED );
    assertSpotify(err, "Could not set connection type.");
    pthread_mutex_lock(&g_notify_mutex);

    while (true) {
        if (next_timeout == 0) {
            while(!g_notify_do)
                pthread_cond_wait(&g_notify_cond, &g_notify_mutex);
        } else {
            time_t now = time(NULL);
            struct timespec ts;
            ts.tv_sec = now;
            ts.tv_sec = now / 1000000;
            ts.tv_sec += next_timeout / 1000;
            ts.tv_nsec += (next_timeout % 1000) * 1000000;
            pthread_cond_timedwait(&g_notify_cond, &g_notify_mutex, &ts);
        }

        g_notify_do = false;
        pthread_mutex_unlock(&g_notify_mutex);
        do {
            sp_session_process_events(g_session, &next_timeout);
        } while (next_timeout == 0);
        pthread_mutex_lock(&g_notify_mutex);
    }

    return 0;
}

问题是，即使我的帐户有大约10个播放列表，sp_playlistcontainer_num_playlists也会返回0。

我的系统：具有MinGW的Windows 7 x64。

我究竟做错了什么？

最佳答案

查看jukebox.c的来源，似乎您应该确保在尝试向播放列表容器查询播放列表之前已完全加载了播放列表容器。
因此，如果我对它的理解正确，则应为container_loaded添加一个回调。
我还认为您应该设置一个回调，以便在用户登录时收到通知，并且在登录时应尝试获取播放列表容器。这样的事情可能会有所帮助：

static sp_playlistcontainer_callbacks pc_callbacks = {
   NULL, /* playlist_added */
   NULL, /* playlist_removed */
   NULL, /* playlist_moved */
   &container_loaded,
};
static sp_session_callbacks session_callbacks = {
   &logged_in,
   &notify_main_thread,
   NULL, /* music_delivery */
   NULL, /* metadata_updated */
   NULL, /* play_token_lost */
   NULL, /* log_message */
   NULL  /* end_of_track */
};
static void container_loaded(sp_playlistcontainer *pc, void *userdata)
{
   // container is fully loaded now it should be safe to query the container
   int num_playlists = sp_playlistcontainer_num_playlists(pc);
}
static void logged_in(sp_session *sess, sp_error error)
{
    // get playlist when user is logged in
    sp_playlistcontainer *pc = sp_session_playlistcontainer(sess);

    // add callbacks
    sp_playlistcontainer_add_callbacks(
    pc,
    &pc_callbacks,
    NULL);
    /* rest of code */
}