音乐播放器

public class MainActivity extends AppCompatActivity {    private ListView mLv;    // 获取外部存储的 音频文件 也可以 修改为 视频 Vedio 或内部存储    private Uri mediaUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;    private SimpleCursorAdapter adapter;    private MediaPlayer mPlayer;//播放音频    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mLv = (ListView) findViewById(R.id.lv);        //得到解析器对象        ContentResolver resolver = getContentResolver();        Cursor cursor = resolver.query(mediaUri,                new String[] { MediaStore.Video.Media._ID,                        MediaStore.Video.Media.DISPLAY_NAME,                        MediaStore.Video.Media.DATA,                        MediaStore.Video.Media.TITLE }, null, null, null);        adapter = new SimpleCursorAdapter(MainActivity.this,                R.layout.item_layout,                cursor,                new String[] { MediaStore.Video.Media.DISPLAY_NAME, MediaStore.Video.Media.DATA, MediaStore.Video.Media.TITLE },                new int[] { R.id.diaplayname_tv, R.id.data_tv, R.id.title_tv },                SimpleCursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);        mLv.setAdapter(adapter);        mLv.setOnItemClickListener(new AdapterView.OnItemClickListener() {            @Override            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {                // TODO Auto-generated method stub                Cursor c = (Cursor) adapter.getItem(position);                String path = c.getString(c.getColumnIndex(MediaStore.Video.Media.DATA));                // 系统播放音频文件//                Intent intent = new Intent();//                intent.setAction(Intent.ACTION_VIEW);//隐式意图跳转， 会根据内容的不同， 打开相应的功能//                intent.setDataAndType(Uri.fromFile(new File(path)), "audio/*");//                startActivity(intent);                if(mPlayer!=null){                    mPlayer.release();//释放资源                }                mPlayer = MediaPlayer.create(MainActivity.this,Uri.parse(path));                mPlayer.start();            }        });    }    @Override    protected void onStop() {        super.onStop();        if(mPlayer!=null && mPlayer.isPlaying())        {            mPlayer.stop();        }    }}