userLocationGet.swift

import UIKit
import CoreLocation
import MapKit

class ViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {
    let locationManager: CLLocationManager? = CLLocationManager()

    @IBOutlet weak var mapView: MKMapView!
    
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        locationManager?.delegate = self
        locationManager?.distanceFilter = kCLLocationAccuracyNearestTenMeters
        locationManager?.desiredAccuracy = kCLLocationAccuracyBest
        mapView.delegate = self
        mapView.showsUserLocation = true
        mapView.userTrackingMode = .followWithHeading
    }//viewDidLoad
    
    override func viewDidAppear(_ animated: Bool) {
        if CLLocationManager.authorizationStatus() == .notDetermined{
            locationManager?.requestWhenInUseAuthorization()
            locationManager?.startUpdatingLocation()
        }else if CLLocationManager.authorizationStatus() == .denied || CLLocationManager.authorizationStatus() == .restricted {
            DispatchQueue.main.async(){
                let alertController = UIAlertController(title: "定位權限已關閉", message: "如要變更權限，請至 設定 > 隱私權 > 定位服務 開啟", preferredStyle: .alert)
                let okAction = UIAlertAction(title: "ok", style: .default, handler: nil)
                alertController.addAction(okAction)
                self.present(alertController, animated: true, completion: nil)
            }//DispatchQueue
        }else if CLLocationManager.authorizationStatus() == .authorizedWhenInUse{
            locationManager?.startUpdatingLocation()
        }//if
    }//ViewWillAppear
    
    
    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidAppear(animated)
        locationManager?.stopUpdatingLocation()//離開畫面就不要再更新地理資訊了
    }//viewDidDisappear
    
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        if (status == CLAuthorizationStatus.denied){
            let alertController = UIAlertController(title: "定位權限已關閉", message: "如要取得咖啡館資訊，請至 設定 > 隱私權 > 定位服務 開啟定位功能", preferredStyle: .alert)
            let okAction = UIAlertAction(title: "ok", style: .default, handler: nil)
            alertController.addAction(okAction)
            self.present(alertController, animated: true, completion: nil)
            
        }//if
    }//locationManager
    
}