Android 中的 SeekBar 和媒体播放器

xml
    android:id="@+id/seekBar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:max="100"
    android:progress="50" />

java
public class MainActivity extends AppCompatActivity {
    private SeekBar seekBar;
    private MediaPlayer mediaPlayer;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        seekBar = findViewById(R.id.seekBar);
        mediaPlayer = MediaPlayer.create(this, R.raw.song);
        seekBar.setMax(mediaPlayer.getDuration());
        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                if (fromUser) {
                    mediaPlayer.seekTo(progress);
                }
            }
            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                mediaPlayer.pause();
            }
            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                mediaPlayer.start();
            }
        });
    }
    public void play(View view) {
        mediaPlayer.start();
    }
    public void pause(View view) {
        mediaPlayer.pause();
    }
    public void stop(View view) {
        mediaPlayer.stop();
        mediaPlayer = MediaPlayer.create(this, R.raw.song);
        seekBar.setProgress(0);
    }
}