IllegalArgumentException：不支持sortOrder

Question

  public List<String> getAllArtists(Context context) {

       List<String> artists = new ArrayList<String>();
       String[] projection2 = {MediaStore.Audio.Media.ARTIST};
       String sortOrder = MediaStore.Audio.Artists.ARTIST;
       Uri songUri = Uri.parse("content://com.google.android.music.MusicContent/audio");
       CursorLoader cl2 = new CursorLoader(context,
                songUri, projection2, null, null, sortOrder);

       cursor = cl2.loadInBackground();

             while (cursor.moveToNext()) {
               if (cursor.getString(0).length()>0){
                if (!artists.contains(cursor.getString(0)))
                 artists.add(cursor.getString(0));
                }}

            cursor.close();

return artists;}

Answer 1

您使用的是一个由Google Play音乐应用程序专门处理的Uri，而不是Android媒体系统。(com.google.android.music是Play Music的包名。）我可以想象

a）播放音乐API不能与AndroidmediastoreAPI混合，

b）播放音乐内容提供程序不支持SQL排序，

MediaStore.Audio.Media.INTERNAL_CONTENT_URI
MediaStore.Audio.Media.EXTERNAL_CONTENT_URI

Collections.sort(artists);