ExoPlayer 没有从特定位置启动视频android studio

如何解决ExoPlayer 没有从特定位置启动视频android studio

我想在 exoPlayer 中开始一个视频，以便在开始时从特定位置开始。但它总是从 0 位置开始。在重新启动时停止活动后，它也不会从当前位置开始，而是从初始位置开始。请帮帮我。

///////////////////////////////////////////// ///////////////////////////////////////////////// ///////////////////////////////////////////////// ///////////////////////////////////////////////// /////

public class VideoDetails extends AppCompatActivity{

PlayerView playerView;
SimpleExoPlayer player;
String videoURL = "https://webflix1122.s3.ap-south-1.amazonaws.com/cokestudio.mkv";
private long playBackPosition = 20000;
ProgressBar loadingBar;





    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_video_details);

        playerView = findViewById(R.id.player_view);
        loadingBar = findViewById(R.id.loading_bar);

    }


    @Override
    protected void onStart() {
        super.onStart();


        player = ExoPlayerFactory.newSimpleInstance(this);
        playerView.setPlayer(player);


        DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(this,Util.getUserAgent(this,"MyApp"));
        MediaSource videoSource = new ExtractorMediaSource.Factory(dataSourceFactory).createMediaSource(Uri.parse(videoURL));



        player.prepare(videoSource);
        player.seekTo(playBackPosition);
        player.setPlayWhenReady(true);
        player.addListener(new Player.EventListener() {
            @Override
            public void onPlayerStateChanged(boolean playWhenReady,int playbackState) {
                switch (playbackState){
                    case ExoPlayer.STATE_READY:
                        loadingBar.setVisibility(View.GONE);
                        break;
                    case ExoPlayer.STATE_BUFFERING:
                        loadingBar.setVisibility(View.VISIBLE);
                        break;
                }

            }
        });
    }


    @Override
    protected void onPause() {
        super.onPause();
        player.setPlayWhenReady(false);
    }

    @Override
    protected void onResume() {
        super.onResume();
        player.setPlayWhenReady(true);
    }

    @Override
    protected void onStop() {
        super.onStop();
        playBackPosition = player.getCurrentPosition();
        playerView.setPlayer(null);
        player.release();




    }

    @Override
    protected void onRestart() {
        super.onRestart();
        player.seekTo(playBackPosition);
        player.setPlayWhenReady(true);

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        player = null;
    }


}