Flutter Spotify - 如何获得基于种子的推荐

Question

使用 Flutter Package spotify-dart，我正在尝试根据用户播放列表中的歌曲获得曲目推荐。

到目前为止的代码：

  // Function that returns a list of recommendation tracks
  void getRecommendations() {
    List<RecommendationsSeed> _seeds = List<RecommendationsSeed>();
    Recommendations _recommendations = Recommendations();
    Map<String, dynamic> _json;

    _json = {
      // I would like to use this song(Photograph - Ed Sheeran) as a seed 
      'id': 'spotify:track:6XLww4MprrLCvWpVXD9K7S',
      'type': 'track'
    };

    _seeds.add(RecommendationsSeed.fromJson(_json));

    _recommendations.seeds = _seeds;

    List<TrackSimple> _tracks = _recommendations.tracks;

    _tracks.forEach((element) {
      print(element.name);
    });

  }

但是，_tracks 仍然为空，因此我收到错误消息 NoSuchMethodError: The method 'forEach' was called on null.

我猜我添加种子的实现是错误的。从种子中获取推荐的正确方法是什么？

Answer 1

以下是根据种子获取推荐的方法。

// Spotify object
var _spotify = SpotifyApi(_credentials);

void getRecommendations() async {
  Recommendations _recommendations = await _spotify.recommendations.get(
    seedTracks: ['5uaIbU3oHHcSOK6WFNK5nj'],
    limit: 10,
  );

  List<TrackSimple> _tracks = _recommendations.tracks;

  _tracks.forEach((element) {
    debugPrint(element.name);
  });
}