我尝试接收使用新MediaSession类媒体按钮presses，到目前为止，我一直不成功。有没有人管理使用新类来接待他们？

I’m attempting to receive media button presses using the new MediaSession class and so far I’ve been unsuccessful. Has anyone managed to receive them using the new class?

我已经成功地创造一个MediaSession，并用它来更新远程显示（在车载娱乐系统）上的歌曲信息，但到目前为止，我无法接收按钮presses从中，耳机控件，以及蓝牙耳机控制。

I’ve been successful in creating a MediaSession and using it to update song information on a remote display (an in-car entertainment system) but so far I’m unable to receive button presses from it, headphone controls, and controls on Bluetooth headsets.

在我创建我执行的，我用它来播放音频服务下面的媒体会话：

After I create the media session I’m executing the following in a service that I use to play audio:

    _mediaSession = new MediaSession(getApplicationContext(), Global.PACKAGE_NAME + "." + TAG);

    if (_mediaSession == null) {
        _log.e(TAG, "initMediaSession: _mediaSession = null");
        return;
    }

    _mediaSessionToken = _mediaSession.getSessionToken();

    _mediaSession.setCallback(new Callback() {
        public boolean onMediaButtonEvent(Intent mediaButtonIntent) {
            _log.d(TAG, "onMediaButtonEvent called: " + mediaButtonIntent);             
            return false;
        }

        public void onPause() {
            Log.d(TAG, "onPause called (media button pressed)");                
            super.onPause();
        }

        public void onPlay() {
            Log.d(TAG, "onPlay called (media button pressed)");             
            super.onPlay();
        }

        public void onStop() {
            Log.d(TAG, "onStop called (media button pressed)");             
            super.onStop();
        }
    });             

     _mediaSession.setFlags(MediaSession.FLAG_HANDLES_MEDIA_BUTTONS | MediaSession.FLAG_HANDLES_TRANSPORT_CONTROLS);

    PlaybackState state = new PlaybackState.Builder()
    .setActions(PlaybackState.ACTION_PLAY)
    .setState(PlaybackState.STATE_STOPPED, PlaybackState.PLAYBACK_POSITION_UNKNOWN, SystemClock.elapsedRealtime())
    .build();

    _mediaSession.setPlaybackState(state);

    _mediaSession.setActive(true);

但我仍然没有收到任何按钮presses。

but I’m still not receiving any button presses.

任何人有什么想法？

感谢

更新变更后

    PlaybackState state = new PlaybackState.Builder()
    .setActions(PlaybackState.ACTION_PLAY)
    .setState(PlaybackState.STATE_STOPPED, PlaybackState.PLAYBACK_POSITION_UNKNOWN, SystemClock.elapsedRealtime())
    .build();

到

    PlaybackState state = new PlaybackState.Builder()
    .setActions(PlaybackState.ACTION_PLAY)
    .setState(PlaybackState.STATE_STOPPED, PlaybackState.PLAYBACK_POSITION_UNKNOWN, 0)
    .build();

我现在通过onMediaButtonEvent（）回调接收按钮preSS通知（如被通知KEY code_MEDIA_PAUSE是pressed），但onPlay（），在onPause（），和的onStop（）永远不会被调用，任何想法，为什么？

I'm now receiving button press notifications via the onMediaButtonEvent() callback (such as being notified that KEYCODE_MEDIA_PAUSE was pressed) but onPlay(), onPause(), and onStop() are never being called, any idea why?

推荐答案

onMediaButtonEvent（..）在MediaSession.Callback的默认实现。在您的code，如果你调用super.onMediaButtonEvent（..），然后根据不同的按键codeS正确的回调即 onPlay（），的onPause（）将被调用。

onMediaButtonEvent(..) has a default implementation in MediaSession.Callback. In your code if you call super.onMediaButtonEvent(..), then depending on the keycodes the correct callback namely onPlay(), onPause() will be called.

您可以看看在 MediaSession.java