怎么在Android中利用SeekBar实现音乐播放器功能

package my.com.mymusicp;import android.app.Service;import android.content.Intent;import android.media.MediaPlayer;import android.os.Bundle;import android.os.IBinder;import android.os.Message;import android.os.RemoteException;import android.support.annotation.Nullable;import android.util.Log;import java.io.IOException;import java.util.Timer;import java.util.TimerTask;public class MyMusicService extends Service {  private String tag="MyMusicService";  private MediaPlayer mediaPlayer;  @Override  public void onCreate() {    super.onCreate();    mediaPlayer = new MediaPlayer();  }  @Nullable  @Override  public IBinder onBind(Intent intent) {    return new MyMusicBinder();  }  class MyMusicBinder extends IMyMusicService.Stub{    @Override    public void play() throws RemoteException {      playmusic();    }    @Override    public void pause() throws RemoteException {     pausemusic();    }    @Override    public void stop() throws RemoteException {      stopmusic();    }    @Override    public void continuePlay() throws RemoteException {      rePlayMusic();    }    @Override    public void seekPlayProgress(int position) throws RemoteException {      seekPlayPositiom(position);    }  }  //播放音乐  public void playmusic(){    mediaPlayer.reset();    String url = "sdcard/Music/Fade.mp3";    Log.i(tag,url);    try {      mediaPlayer.setDataSource(url);      mediaPlayer.prepare();    } catch (IOException e) {      e.printStackTrace();    }     // might take long! (for buffering, etc)    mediaPlayer.start();    //更新播放进度条    seekPlayProgress();  }  public void pausemusic(){    mediaPlayer.pause();    Log.i(tag,"暂停播放");  }  public void stopmusic(){    mediaPlayer.reset();    Log.i(tag,"停止播放");    mediaPlayer.stop();  }  @Override  public void onDestroy() {    super.onDestroy();  }  public void seekPlayPositiom(int positon){    Log.i(tag,"设置播放位置");    mediaPlayer.seekTo(positon);  }  public void seekPlayProgress(){         final int duration=mediaPlayer.getDuration();    //计时器对象    final Timer timer=new Timer();    final TimerTask task=new TimerTask() {      @Override      public void run() {        //开启线程定时获取当前播放进度        int currentposition=mediaPlayer.getCurrentPosition();        //利用message给主线程发消息更新seekbar进度        Message ms=Message.obtain();        Bundle bundle=new Bundle();        bundle.putInt("duration",duration);        Log.i(tag,"歌曲总长度"+duration);        bundle.putInt("currentposition",currentposition);        Log.i(tag,"当前长度"+currentposition);        //设置发送的消息内容        ms.setData(bundle);        //发送消息        MainActivity.handler.sendMessage(ms);      }    };     timer.schedule(task,300,500);    //当播放结束时停止播放    mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {      @Override      public void onCompletion(MediaPlayer mp) {        Log.i(tag,"取消计时任务");        timer.cancel();        task.cancel();      }    });  }  public void rePlayMusic() {    Log.i(tag, "继续播放音乐");    mediaPlayer.start();  }}