Question

我的手机上有一个应用程序可以保持音频对焦，即使没有声音播放也是如此。我想作为一名应用程序开发人员，如果我能够通知用户它是哪个应用程序，或者我是否可以判断我的应用程序是否具有音频焦点？

Answer 1

我强烈怀疑是否有任何公共API可以告诉您目前哪个应用程序具有焦点。

您可以通过请求来跟踪您的应用是否具有音频焦点，例如：

AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
boolean requestGranted = AudioManager.AUDIOFOCUS_REQUEST_GRANTED == audioManager.requestAudioFocus(listener, AudioManager.STREAM_MUSIC,
                    AudioManager.AUDIOFOCUS_GAIN);
if(requestGranted){
   // you now has the audio focus
}

当您请求并放弃焦点时，您应该确保维护一个单个侦听器实例，see my answer here以解决音频焦点的常见问题

以下是onAudioFocusChange()的示例：

@Override
public void onAudioFocusChange(int focus) {

  switch (focus) {
    case AudioManager.AUDIOFOCUS_LOSS:
        Log.d(TAG,"AUDIOFOCUS_LOSS");
        // stop and release your player
        break;
    case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
        Log.d(TAG,"AUDIOFOCUS_LOSS_TRANSIENT");
        // pause your player
        break;
    case AudioManager.AUDIOFOCUS_GAIN:
        Log.d(TAG,"AUDIOFOCUS_GAIN");
        // restore volume and resume player if needed
        break;
    case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
        Log.d(TAG,"AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK");
        // Lower volume
        break;
   }
}

Answer 2

也许这个方法可以满足您的需求： AudioManager.isMusicActive() http://developer.android.com/reference/android/media/AudioManager.html#isMusicActive%28%29

Android - 是否可以找出哪个应用有音频焦点？

2 个答案: