在服务中使用Mediaplayer在后台播放视频 [英] Play video in background using mediaplayer in service

问题描述

我正在开发一个可以播放youtube视频的应用程序，如果用户按下主屏幕按钮，则用户可以听到音频，然后可以再次观看视频. 因此，我使用Mediaplayer和setDisplay surfaceview来观看视频，但是当按下home键时它不能保持播放器播放，我知道Service可以在后台执行长时间运行的操作，并且不提供用户界面.因此，我创建了一个包含Mediaplayer的服务

I'm develop a app that can play video from youtube, if user pressed home button, user can hear the audio and then they can back to see video again. So, i use Mediaplayer and setDisplay surfaceview to it to see video, but it can't keep player play when home pressed, i know Service can perform long-running operations in the background and does not provide a user interface. so, i create a service that hold Mediaplayer

public class VideoPlayerService extends Service implements MediaPlayer.OnPreparedListener {

    private static final String TAG = "VideoPlayerService";

    public MediaPlayer mPlayer;

    public static int position;

    private final IBinder mBinder = new LocalBinder();

    @Override
    public IBinder onBind(Intent intent) {
       Log.d(TAG, "service in onBind");
       return mBinder;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        mPlayer = new MediaPlayer();
        Log.d(TAG, "service created");
    }

    public class LocalBinder extends Binder {
        public VideoPlayerService getService() {
            return VideoPlayerService.this;
        }
    }

    @Override
    public int onStartCommand(final Intent intent, final int flags, final int startId) {
        return 1;
    }


    public IBinder onUnBind(final Intent arg0) {
        return null;
    }
}

我的活动绑定到它以获得服务实例，并将mediaplayer实例获取到setDisplay surfaceview上.但似乎，我可以setDisplay到媒体播放器，因为根据此，服务实例不会在我的活动离开onCreate()之前返回 android-how-do-i-wait-直到一项服务实际上已连接

And my activity bind on it to get service instance and get mediaplayer instance to setDisplay surfaceview to it. But it seem like, i can setDisplay to mediaplayer because service instance do not return before my activity leave onCreate() acording to this android-how-do-i-wait-until-a-service-is-actually-connected

但是表面是通过活动立即创建的，并且我不能setDisplay到媒体播放器来显示视频，我如何克服这个问题，这是我的活动:

but surface created imediately with activity, and i can't setDisplay to mediaplayer to show video, how can i surpass this problem, here is my activity:

public class VideoPlayerActivity extends Activity implements SurfaceHolder.Callback, MediaController.MediaPlayerControl, GetStreamUrlTest.IPlayerListener, MediaPlayer.OnPreparedListener {

static final String TAG = "VideoPlayerActivity";

public MediaController mMediaController;

public SurfaceView surfaceView;
public SurfaceHolder holder;

public VideoItem mVideoItem;

public int position = 0;

private VideoPlayerService mVideoPlayerService;

private boolean mBounded;

private ServiceConnection mServiceConnection = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
        VideoPlayerService.LocalBinder localBinder = (VideoPlayerService.LocalBinder)
                iBinder;
        mVideoPlayerService = localBinder.getService();
        mBounded = true;
        Log.d(TAG, "Service connected");

    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {
        Log.e(TAG, "Service has unexpectedly disconnected");
        mBounded = false;
    }
};

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.videoplayer);

    Log.d(TAG, "in Oncreate");

    mMediaController = new MediaController(this);
    mMediaController.setMediaPlayer(this);
    mMediaController.setAnchorView(surfaceView);

    Intent intent = getIntent();
    mVideoItem = (VideoItem) intent.getParcelableExtra(ConstantFields.VIDEO_ITEM);

    getWindow().setFormat(PixelFormat.UNKNOWN);
    surfaceView = (SurfaceView) findViewById(R.id.surfaceView);
    holder = surfaceView.getHolder();
    holder.setFixedSize(800, 480);
    holder.addCallback(this);
    holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

@Override
protected void onStart() {
    super.onStart();
    Intent serviceIntent = new Intent(this, VideoPlayerService.class);
    bindService(serviceIntent, mServiceConnection, Context.BIND_AUTO_CREATE);
}

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

}

@Override
protected void onStop() {
    super.onStop();
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    if (!mMediaController.isShowing()){
        mMediaController.show();
    } else {
        mMediaController.hide();
    }
    return false;
}

@Override
public void onBackPressed() {
    super.onBackPressed();
}

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

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

@Override
public void doPlayVideo(VideoItem videoItem){
    Log.d(TAG,"in DO Play");
    mVideoPlayerService.mPlayer.reset();
    try {
        mVideoPlayerService.mPlayer.setDataSource(this, Uri.parse(videoItem.getStreamUrl()));

        mVideoPlayerService.mPlayer.prepareAsync();
        mVideoPlayerService.mPlayer.setOnPreparedListener(this);

    } catch (IOException e) {
        e.printStackTrace();
    }
}

@Override
public void onPrepared(MediaPlayer mediaPlayer) {
    mVideoPlayerService.mPlayer.start();
}

@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
    mVideoPlayerService.mPlayer.setDisplay(surfaceHolder);
    doPlay(mVideoItem)
    Log.d(TAG, "In surface Created");
}

@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i2, int i3) {
}

@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
}
}

推荐答案

我只是将surfaceHolder作为类的字段存储在surfaceCreated(SurfaceHolder surfaceHolder)中，然后在创建服务时使用它. 对不起一个愚蠢的问题，但是我认为这段代码对于任何想在服务中使用Mediaplayer播放音频或视频的人都有用

I just store surfaceHolder in surfaceCreated(SurfaceHolder surfaceHolder) as a field of class and then use it when service created. Sorry for a stupid question, but i think this code can be useful for anyone who want to use mediaplayer in service to play a audio or video

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