使用Flutter软件包 飞碟我试图根据用户在播放列表中的歌曲获得曲目推荐。
到目前为止,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
仍然是空的,因此我得到一个错误信息说 NoSuchMethodError: The method 'forEach' was called on null.
我想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?
下面是如何基于种子获得推荐。
// 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);
});
}