若要在應用程式在背景時啟用音訊播放,應用程式應在播放程式處於「已準備」狀態時,以true為引數呼叫enableAudioPlaybackInBackground
MediaPlayer的API。
_mediaPlayer.enableAudioPlaybackInBackground(true);
當應用程式在回應手機等事件期間失去對音訊焦點的控制時,應該暫停播放。 下列程式碼片段示範如何實作OnAudioFocusChangeListener
:
/**
* Register the AudioFocus Change listener to track Audio focus from device.
*/
AudioManager.OnAudioFocusChangeListener onAudioFocusChangeListener = new AudioManager.OnAudioFocusChangeListener(){
@Override
public void onAudioFocusChange(int focusChange){
switch(focusChange){
case AudioManager.AUDIOFOCUS_GAIN:
break;
case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
/* lower output volume*/
break;
case AudioManager.AUDIOFOCUS_LOSS:
case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
if(_lastKnownStatus ==MediaPlayerStatus.PLAYING)
_mediaPlayer.pause();
break;
}
}
};
AudioManager audioManager = (AudioManager) getActivity().getApplicationContext().getSystemService(Context.AUDIO_SERVICE);
audioManager.requestAudioFocus(onAudioFocusChangeListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);