在GameActivity里面修改：
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
AudioManager mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
int currentVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
switch (keyCode) {
case KeyEvent.KEYCODE_VOLUME_UP:// 音量增大
mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume+1, 1);
break;
case KeyEvent.KEYCODE_VOLUME_DOWN:// 音量减小
mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, currentVolume-1, 1);
break;
case KeyEvent.KEYCODE_BACK:// 返回键
//jniOnCallCppEvent();
return true;
//return super.onKeyDown(keyCode, event);
default:
break;
}
return true;
//return super.onKeyDown(keyCode, event);
}