如何确定其他应用程序失去音频焦点以便我可以启动我的播放器

Question

我在网上看到很多Android播放器一开始播放其他应用程序就失去焦点并停止播放。

另一方面，一旦获得焦点的应用程序停止播放，焦点松散的应用程序就会再次开始播放。

任何人都可以建议我在这里缺少什么来在我的应用程序中实现相同的目标吗？我希望其他应用程序停止播放我的应用程序应该获得焦点并开始播放..

private void setupAudioManager() {
        audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
        audioManager.requestAudioFocus(audioFocusListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
        audioFocusListener = new OnAudioFocusChangeListener() {
            @Override
            public void onAudioFocusChange(int focusChange) {
                switch (focusChange) {
                    case AUDIOFOCUS_GAIN:
                        if (mediaPlayer == null) setupMediaPlayer();
                        else if (!mediaPlayer.isPlaying()) {
                            play();
                        }
                        mediaPlayer.setVolume(MEDIA_PLAYER_LEFT_VOLUME, MEDIA_PLAYER_RIGHT_VOLUME);
                        break;

                    case AUDIOFOCUS_LOSS:
                        if (isPlaying()) {
                            Intent intent = new Intent("HomeActivity");
                            intent.putExtra("playerState", "pause");
                            LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(intent);
                        }

                        break;

                    case AUDIOFOCUS_LOSS_TRANSIENT:
                        if (isPlaying()) pause();
                        break;

                    case AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
                        if (isPlaying()) mediaPlayer.setVolume(MEDIA_PLAYER_LEFT_VOLUME_LOW,
                                MEDIA_PLAYER_RIGHT_VOLUME_LOW);
                        break;

                }
            }
        };
    }

正在寻找您的建议。

Answer 1

这是我的发现

In case of Permanent loss of focus

如果音频焦点丢失是永久性的 (AUDIOFOCUS_LOSS)，则另一个应用程序正在播放音频。您的应用应立即暂停播放。此时您的应用将永远不会收到 AUDIOFOCUS_GAIN 回调。要重新开始播放，用户必须采取明确的操作，例如在通知或应用程序中按下播放传输控件 UI.

暂停后您的应用应等待一小段时间，然后停止其媒体会话以释放资源并放弃音频焦点。延迟停止调用让用户有机会重新开始您的应用程序的播放。如果您的应用因为用户不小心启动了请求音频焦点的其他应用而变得无声，这将很有用。

The following code snippet demonstrates how to implement the OnAudioFocusChangeListener and its onAudioFocusChange() callback. Notice the use of a Handler to delay the stop callback on a permanent loss of audio focus.

private Handler mHandler = new Handler();
AudioManager.OnAudioFocusChangeListener afChangeListener =
  new AudioManager.OnAudioFocusChangeListener() {
    public void onAudioFocusChange(int focusChange) {
      if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {
        // Permanent loss of audio focus
        // Pause playback immediately
        mediaController.getTransportControls().pause();
        // Wait 30 seconds before stopping playback
        mHandler.postDelayed(mDelayedStopRunnable,
          TimeUnit.SECONDS.toMillis(30));
      }
      else if (focusChange == AUDIOFOCUS_LOSS_TRANSIENT) {
        // Pause playback
      } else if (focusChange == AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK) {
        // Lower the volume, keep playing
      } else if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {
        // Your app has been granted audio focus again
        // Raise volume to normal, restart playback if necessary
      }
    }
  };

The handler uses a Runnable that looks like this:

private Runnable mDelayedStopRunnable = new Runnable() {
    @Override
    public void run() {
        mediaController.getTransportControls().stop();
    }
};

To ensure the delayed stop does not kick in if the user restarts playback, call mHandler.removeCallbacks(mDelayedStopRunnable) in response to any state changes. For example, call removeCallbacks() in your Callback's onPlay(), onSkipToNext(), etc. You should also call this method in your service's onDestroy() callback when cleaning up the resources used by your service.

如何确定其他应用程序失去音频焦点以便我可以启动我的播放器

How to determine that other app lose the audio focus so that i can start my player

android

android-mediaplayer

android-audiomanager