switch CLLocationManager.authorizationStatus() {
        case .notDetermined:
            locationManager.requestWhenInUseAuthorization() // First time lanch app need to get authorize from user
            fallthrough
        case .authorizedWhenInUse:
            locationManager.startUpdatingLocation() // Start location
        case .denied:
            let alertController = UIAlertController (title: "定位失敗", message: "無法取得使用者目前所在位置", preferredStyle: .alert)

            let settingsAction = UIAlertAction(title: "設定", style: .default) { (_) -> Void in

                guard let settingsUrl = URL(string: UIApplication.openSettingsURLString) else {
                    return
                }

                if UIApplication.shared.canOpenURL(settingsUrl) {
                    UIApplication.shared.open(settingsUrl, completionHandler: { (success) in
                        print("Settings opened: \(success)") // Prints true
                    })
                }
            }
            alertController.addAction(settingsAction)
            let cancelAction = UIAlertAction(title: "確認", style: .default, handler: nil)
            alertController.addAction(cancelAction)

            present(alertController, animated: true, completion: nil)
        default:
            break
        }