Android：如何在服务类中使用mediaController？

我有一个通过MediaPlayer作为服务播放广播的应用程序。可以在服务类中使用MediaController吗？ 问题是我可以使用findviewbyd

我试着让我的线路布置在预先准备好的方法上

public class RadioPlayer extends Service implements OnPreparedListener, MediaController.MediaPlayerControl {
  @Override
  public void onCreate() {
  super.onCreate();
  mediaPlayer = new MediaPlayer();
  mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
  mediaPlayer.setOnPreparedListener(this);
  mediaController = new MediaController(this, false); mediaPlayer.setDataSource(url);
  mediaPlayer.prepareAsync(); 
}

@Override
  public void onPrepared(MediaPlayer mediaPlayer) {
  mediaPlayer.start();
  mediaController.setMediaPlayer(this);
  LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
  View layout = inflater.inflate(R.layout.main, (ViewGroup) findViewById(R.id.main_program_view));
  mediaController.setAnchorView(layout);
}
}

main.xml文件

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/main_program_view"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:background="#FFFFFF"
        android:orientation="vertical" >  

        <TextView
            android:id="@+id/now_playing_text"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="30dp"
            android:gravity="center"
            android:text="@string/na_antenie"
            android:textColor="#333333" />    
</LinearLayout>

---

您不能在服务中使用mediacontroller类。服务不包含GUI，因此您的服务无法识别findViewById。 而是创建一个实现mediaController的活动，然后创建服务并将其绑定到活动。因此，您的服务中有mediaPlayer，活动中有控制器

这是活动类的概述

public class MusicPlayerActivity extends Activity implements MediaController.MediaPlayerControl{
//Do all the stuff
void initMusic(){
    mMediaController = new MediaController(this,false);
    //Note do not create any variable of mediaplayer
    mMediaController.setMediaPlayer(this);       
    mMediaController.setAnchorView(findViewById(R.id.anchorText));

    new Thread(new Runnable() {

        @Override
        public void run() {
        startService(new Intent("PLAY_MUSIC"));
        }
    }).start();
        MusicService.setPathOfSong("Provide the path");

}
}

这是服务类的概述

public class MusicService extends Service implements MediaPlayer.OnPreparedListener {
private MediaPlayer mMediaPlayer;
private static String pathOfSong;
public int onStartCommand(Intent intent, int flags, int startId) {
        mMediaPlayer=new MediaPlayer();
        mMediaPlayer.setOnPreparedListener(this);
        //Other stuff
}
public static void setPathOfSong(String path)
{
    pathOfSong=path;
}
}

---

我也有同样的问题，我不能让它像你那样工作

解决方案是在活动中绑定服务，然后您可以从活动中访问服务中运行的MediaPlayer

请注意，要以这种方式运行，您的服务必须定义了所有必要的方法，如getCurrentPosition等

在活动中添加绑定工具：

/****************************************************************** 
 * 
 * Defines callbacks for service binding, passed to bindService() 
 * 
 * ************************************************************** */
private ServiceConnection mConnection = new ServiceConnection() {

    @Override
    public void onServiceConnected(ComponentName className,
            IBinder service) {
        // We've bound to LocalService, cast the IBinder and get LocalService instance
        LocalBinder binder = (LocalBinder) service;
        mService = binder.getService();
        mBound = true;
    }

    @Override
    public void onServiceDisconnected(ComponentName arg0) {
        mBound = false;
    }
};

然后必须修改onStart（）和onStop（）方法以绑定/解除绑定服务

@Override
protected void onStart() {
    super.onStart();
    // Bind to LocalService
    Intent intent = new Intent(this, MusicService.class);
    bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}

@Override
protected void onStop() {
    super.onStop();
    // Unbind from the service
    if (mBound) {
        unbindService(mConnection);
        mBound = false;
    }
}

我后来做的是创建以下方法

public void showMediaControllerHere(){
    if (mBound){
        mc = new MediaController(mpContext);
        mc.setAnchorView(findViewById(R.id.anchorText));
        mc.setMediaPlayer(mService);
        mc.setEnabled(true);
        mc.show(0);
    }
}
@Override
  public boolean onTouchEvent(MotionEvent event) {
    //the MediaController will hide after 3 seconds - tap the screen to make it appear again
    if (first){
          if (mBound){
              showMediaControllerHere();
              first = false;
          }
      }
      else {
          if (mBound){
              mc.show(0);
          }
      }
    return false;
  }

首先是一个布尔值，用于实现是否必须创建mediacontroller，我仅在用户第一次触摸屏幕时创建