以编程方式访问库中的音乐文件 (Android)

Access Music files from library programmatically (Android)

我想访问 Android phone(不是 sdcard)中的音乐库并将其显示在列表中。我想获取与每个文件相关的所有信息,如持续时间、艺术家等。我将如何以编程方式执行此操作?

这就是我为我的一个案例定制的方式:

    public class MusicActivity extends FragmentActivity {
    ListView musiclist;
    Cursor musiccursor;
    int music_column_index;
    int count;
    MediaPlayer mMediaPlayer;



    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        init_phone_music_grid();
    }

    private void init_phone_music_grid() {
        System.gc();
        String[] proj = { MediaStore.Audio.Media._ID,
                MediaStore.Audio.Media.DATA,
                MediaStore.Audio.Media.DISPLAY_NAME,
                MediaStore.Video.Media.SIZE };
        musiccursor = managedQuery(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                proj, null, null, null);
        count = musiccursor.getCount();
        musiclist = (ListView)findViewById(R.id.sample);
        musiclist.setAdapter(new MusicAdapter(getApplicationContext()));

        musiclist.setOnItemClickListener(musicgridlistener);
        mMediaPlayer = new MediaPlayer();
    }

    private OnItemClickListener musicgridlistener = new OnItemClickListener() {
        public void onItemClick(AdapterView parent, View v, int position,
                                long id) {
            System.gc();
            music_column_index = musiccursor
                    .getColumnIndexOrThrow(MediaStore.Audio.Media.DATA);
            musiccursor.moveToPosition(position);
            String filepath = musiccursor.getString(music_column_index);

            finish();


            try {
                if (mMediaPlayer.isPlaying()) {
                    mMediaPlayer.reset();
                }
                mMediaPlayer.setDataSource(filepath);
                mMediaPlayer.prepare();
                mMediaPlayer.start();
            } catch (Exception e) {

            }
        }
    };

    public class MusicAdapter extends BaseAdapter {
        private Context mContext;

        public MusicAdapter(Context c) {
            mContext = c;
        }

        public int getCount() {
            return count;
        }

        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            System.gc();
            TextView tv = new TextView(mContext.getApplicationContext());
            String id = null;
            if (convertView == null) {
                music_column_index = musiccursor
                        .getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME);
                musiccursor.moveToPosition(position);
                id = musiccursor.getString(music_column_index);
                music_column_index = musiccursor
                        .getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE);
                musiccursor.moveToPosition(position);
                //id += " Size(KB):" + musiccursor.getString(music_column_index);
                tv.setText(id);
            } else
                tv = (TextView) convertView;
            return tv;
        }
    }
}
    private void musics(){
    Uri uri = MediaStore.Audio.Media.INTERNAL_CONTENT_URI;
    ContentResolver cr = getContentResolver();
    String[] columns = {MediaStore.Audio.Media.DISPLAY_NAME};//add which column you need here

    Cursor cursor = cr.query(uri, columns, null, null, null);

    if(cursor == null){
        return;
    }
    if(cursor.getCount() > 0){
        cursor.moveToFirst();
        do{
            //read your information here
            String artist = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));

        }while(cursor.moveToNext());
    }

    cursor.close();
}