Android Studio - 尝试从 Android 设备上的音乐目录中读取 MP3 文件

Question

我有一个功能，我从这里的帖子中获得，我正在尝试从设备中读取音乐文件。

   public List<AudioModel> getAllAudioFromDevice(final Context context) {
        final List<AudioModel> tempAudioList = new ArrayList<>();
        Cursor c = getAllTracks(this);


        if (c != null) {
            Log.d("Count :", String.valueOf(c.getCount()));
            while (c.moveToNext()) {
                AudioModel audioModel = new AudioModel();
                String path = c.getString(0);
                String name = c.getString(1);
                String album = c.getString(4);

                audioModel.setaAlbum(album);
                audioModel.setaArtist(artist);
       
                Log.e("Name :" + name, " Album :" + album);
                Log.e("Path :" + path, " Artist :" + artist);

                tempAudioList.add(audioModel);
            }
            c.close();
        } else {
            Log.d("Name :", "No Music");
        }

        return tempAudioList;
    }

    public Cursor getAllTracks(Context context) {
        // gets all tracks
        if (context != null) {
            ContentResolver cr = context.getContentResolver();
            final String[] columns = {track_id, track_no, artist, track_name,
                    album, duration, path, year, composer};
            return cr.query(uri, columns, null, null, null);
        } else {
            return null;
        }
    }

当我运行该应用程序时，它不会列出任何 MP3 文件，但会选择 oog 文件。我上传到模拟器的mp3文件如下：

我也尝试过 EXTERNAL_CONTENT_URI，但没有显示出来。

这是 Theo 建议的“播放列表管理器”应用程序：

抱歉，我对 Android Studio 很陌生，可能遗漏了一些非常明显的东西。有人可以帮忙吗？

Answer 1

你的问题是

Uri uri = MediaStore.Audio.Media.INTERNAL_CONTENT_URI;

改成

Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;

并删除 .DATA 位 光标 c = context.getContentResolver().query(uri, projection, MediaStore.Audio.Media.DATA, null, null) 当您将标准放在那里时。查找查询的语法。将其设置为null，它将起作用

Answer 2

这是我的做法，注意语法

return cr.query(uri, columns, null, null, null)

你有

  Cursor c = context.getContentResolver().query(uri, projection, MediaStore.Audio.Media.DATA, null, null);



 private final String track_id = MediaStore.Audio.Media._ID;
    private final String track_no = MediaStore.Audio.Media.TRACK;
    private final String track_name = MediaStore.Audio.Media.TITLE;
    private final String artist = MediaStore.Audio.Media.ARTIST;
    private final String artist_id = MediaStore.Audio.Media.ARTIST_ID;
    private final String duration = MediaStore.Audio.Media.DURATION;
    private final String album = MediaStore.Audio.Media.ALBUM;
    private final String composer = MediaStore.Audio.Media.COMPOSER;
    private final String year = MediaStore.Audio.Media.YEAR;
    private final String path = MediaStore.Audio.Media.DATA;
    private final String date_added = MediaStore.Audio.Media.DATE_ADDED;
    private final Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;


        public Cursor getAllTracks(Context context) {
        // gets all tracks
        if (context != null) {
            ContentResolver cr = context.getContentResolver();
            final String[] columns = {track_id, track_no, artist, track_name,
                    album, duration, path, year, composer};
            return cr.query(uri, columns, null, null, null);
        } else {
            return null;
        }
    }