Android – 是否可以找出哪个应用有音频焦点？

您可以通过请求来跟踪您的应用是否具有音频焦点,例如：

Au@L_793_4@manager au@L_793_4@manager = (Au@L_793_4@manager) getSy@R_403_2407@service(Context.AUdio_serviCE);
Boolean requestGranted = Au@L_793_4@manager.AUdioFOCUS_requEST_GRANTED == au@L_793_4@manager.requestAudioFocus(listener,Au@L_793_4@manager.STREAM_MUSIC,Au@L_793_4@manager.AUdioFOCUS_GAIN);
if(requestGranted){
   // you Now has the audio focus
}

您应该确保在请求和放弃焦点时维护一个侦听器实例,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 Au@L_793_4@manager.AUdioFOCUS_LOSS:
        Log.d(tag,"AUdioFOCUS_LOSS");
        // stop and release your player
        break;
    case Au@L_793_4@manager.AUdioFOCUS_LOSS_TRANSIENT:
        Log.d(tag,"AUdioFOCUS_LOSS_TRANSIENT");
        // pause your player
        break;
    case Au@L_793_4@manager.AUdioFOCUS_GAIN:
        Log.d(tag,"AUdioFOCUS_GAIN");
        // restore volume and resume player if needed
        break;
    case Au@L_793_4@manager.AUdioFOCUS_LOSS_TRANSIENT_CAN_DUCK:
        Log.d(tag,"AUdioFOCUS_LOSS_TRANSIENT_CAN_DUCK");
        // Lower volume
        break;
   }
}