onResultCallback method

Stream<String> onResultCallback()

原生端回传键值对map到flutter端 map中key为isInChina对应的value，如果为1则判断是在国内，为0则判断是在国外 map中存在key为nearby则判断为已到达设置监听位置附近

Implementation

Stream<String> onResultCallback() {
  Stream<String> result;
  if (result == null) {
    result = _stream.receiveBroadcastStream().cast<String>();
  }
  return result;
}