動的更新seekBar

public class MediaPlayerActivity extends Activity implements Runnable{
    /** Called when the activity is first created. */

    private MediaPlayer mPlayer;
    private ImageButton mPlay;
    private ImageButton mPause;
    private SeekBar mSeekBar;
    private int total;

    public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.main);
	mPlay = (ImageButton) findViewById(R.id.play);
	mPause = (ImageButton) findViewById(R.id.pause);
	mSeekBar = (SeekBar) findViewById(R.id.seekbar);
	mPlayer = MediaPlayer.create(this,R.raw.mp3_file_name);
	mSeekBar.setProgress(0);
	total = mPlayer.getDuration();
	mPause.setVisibility(View.INVISIBLE);
	mPlay.setOnClickListener(new OnClickListener(){
		@Override
		public void onClick(View arg0) {
			// TODO Auto-generated method stub
			mPlayer.start();
			mSeekBar.setMax(total);
			mPlay.setVisibility(View.INVISIBLE);
			mPause.setVisibility(View.VISIBLE);
		}
	});

	mPause.setOnClickListener(new OnClickListener(){
		@Override
		public void onClick(View arg0) {
			// TODO Auto-generated method stub
			if(mPlayer.isPlaying()){
				mPlayer.pause();
				mPlay.setVisibility(View.VISIBLE);
				mPause.setVisibility(View.INVISIBLE);
			}
		}
	});

	mSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {

		@Override
		public void onStopTrackingTouch(SeekBar seekBar) {
			// TODO Auto-generated method stub

		}

		@Override
		public void onStartTrackingTouch(SeekBar seekBar) {
			// TODO Auto-generated method stub

		}

		@Override
		public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
			// TODO Auto-generated method stub
			if(fromUser){
				mPlayer.seekTo(progress);
				mSeekBar.setProgress(progress);
			}
		}
	});

	Thread currentThread  = new Thread(this);
	currentThread.start();

    }

	@Override
	public void run() {
		// TODO Auto-generated method stub
		try {
			while(mPlayer != null){
				int currentPosition = mPlayer.getCurrentPosition();
				Message msg = new Message();
				msg.what = currentPosition;
				threadHandler.sendMessage(msg);
			}
			Thread.sleep(100);
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	private Handler threadHandler = new Handler(){
		public void handleMessage(Message msg){
			//super.handleMessage(msg);
			//txt.setText(Integer.toString(msg.what));
			mSeekBar.setProgress(msg.what);
		}
	};

}