恢复Media Player后失去音频焦点

Question

在暂停并恢复我的静态媒体播放器类后，我无法获得audiofocus。应用获得关注并立即失去关注。我认为这是因为我的AUDIOFOCUS_LOSS外壳不好，但我不知道如何修复。我在应用中定位了API 20。

编辑：当应用程序丢失并从其他应用程序获得焦点并恢复音乐时，一切正常工作。

public class AudioManagerHandler {

private Context context;
private static final String TAG = "AudioManagerHandler";

public AudioManagerHandler(Context context){
    this.context = context;
}

public boolean AudioListener(){

    final AudioManager audioManager = (AudioManager)context.getSystemService(Context.AUDIO_SERVICE);

    final AudioManager.OnAudioFocusChangeListener afChangeListener = new AudioManager.OnAudioFocusChangeListener(){
        @Override
        public void onAudioFocusChange(int i) {
            switch(i){
                case AudioManager.AUDIOFOCUS_GAIN:
                    break;
                case AudioManager.AUDIOFOCUS_GAIN_TRANSIENT:
                    MediaPlayerHandler.pause();
                    break;
                case AudioManager.AUDIOFOCUS_LOSS:
                    MediaPlayerHandler.pause();
                    audioManager.abandonAudioFocus(this);
                    break;
            }
        }
    };

    int focusRequest = audioManager.requestAudioFocus(afChangeListener,AudioManager.STREAM_MUSIC,AudioManager.AUDIOFOCUS_GAIN);

    if(focusRequest==AudioManager.AUDIOFOCUS_REQUEST_GRANTED){
        return true;
    }else{
        return false;
    }
}

我的日志：

07-05 20:26:01.610 4183-4183/com.example.michael.myapplication D/AudioManager: AudioManager dispatching onAudioFocusChange(-1) for android.media.AudioManager$16eb3b8com.example.michael.myapplication.AudioManagerHandler$1$f34c591

如果有任何建议，我将不胜感激。