rog_app/ios/Runner/AppDelegate.swift

import UIKit
import CoreLocation
import Flutter

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate, CLLocationManagerDelegate {
    var locationManager: CLLocationManager?
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    GeneratedPluginRegistrant.register(with: self)

    let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
    let locationServiceChannel = FlutterMethodChannel(name: "location",
                                                      binaryMessenger: controller.binaryMessenger)
    /*
    locationServiceChannel.setMethodCallHandler { (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
      if call.method == "isLocationServiceRunning" {
        result(self.isLocationServiceRunning())
      } else {
        result(FlutterMethodNotImplemented)
      }
    }
    */

        locationServiceChannel.setMethodCallHandler { [weak self] (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
            if call.method == "startLocationService" {
                //self?.startLocationService()
                result(nil)
            } else if call.method == "isLocationServiceRunning" {
                result(self?.isLocationServiceRunning() ?? false)
            } else {
                result(FlutterMethodNotImplemented)
            }
        }

    locationManager = CLLocationManager()
    locationManager?.delegate = self
    locationManager?.requestAlwaysAuthorization()
    locationManager?.startUpdatingLocation()

    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }

  private func isLocationServiceRunning() -> Bool {
    guard let locationManager = locationManager else {
      return false
    }

    let isRunning = locationManager.monitoredRegions.count > 0 || locationManager.location != nil
    return isRunning
  }
}