问如果应用程序关闭，如何在我的颤振应用程序中设置背景位置更新？

EN

import 'package:location/location.dart';
class LocationService {
  UserLocation _currentLocation;
  var location = Location();

  //One off location
  Future<UserLocation> getLocation() async {
    try {
      var userLocation = await location.getLocation();
      _currentLocation = UserLocation(
        latitude: userLocation.latitude,
        longitude: userLocation.longitude,
      );
    } on Exception catch (e) {
      print('Could not get location: ${e.toString()}');
    }
    return _currentLocation;
  }

  //Stream that emits all user location updates to you
  StreamController<UserLocation> _locationController =
  StreamController<UserLocation>();
  Stream<UserLocation> get locationStream => _locationController.stream;
  LocationService() {
    // Request permission to use location
    location.requestPermission().then((granted) {
      if (granted) {
        // If granted listen to the onLocationChanged stream and emit over our controller
        location.onLocationChanged().listen((locationData) {
          if (locationData != null) {
            _locationController.add(UserLocation(
              latitude: locationData.latitude,
              longitude: locationData.longitude,
            ));
          }
        });
      }
    });
  }
}

class UserLocation {
  final double latitude;
  final double longitude;
  final double heading;
  UserLocation({required this.heading, required this.latitude, required this.longitude});
}

Timer? locationUpdateTimer;

    locationUpdateTimer = Timer.periodic(const Duration(seconds: 60), (Timer t) {
      updateLocationToServer();
    });