Обновленная обратная геолокация
Существует ряд примеров, показывающих, как выполнять обратную геолокацию, но ничего нового в реализации в SwiftUI нет. Мой текущий код использует iPhone GPS для генерации координат, которые используются с картами для отображения местоположения. Я также хотел бы отобразить почтовый адрес, поскольку карта без текста, указывающего местоположение, не очень полезна.
Мои вопросы:
- Есть ли у меня весь соответствующий код для реализации обратной геолокации?
- Я видел примеры использования раскадровок и операторов печати для отображения местоположения, но как мне вернуть местоположение в представление Swiftui с закрытием @escape?
import Foundation
import CoreLocation
class LocationManager: NSObject, ObservableObject {
private let locationManager = CLLocationManager()
var currentAddress: String = ""
override init() {
super.init()
self.locationManager.delegate = self
self.locationManager.distanceFilter = 10 // distance before update (meters)
self.locationManager.requestWhenInUseAuthorization()
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.startUpdatingLocation()
}
func startLocationServices() {
if locationManager.authorizationStatus == .authorizedAlways || locationManager.authorizationStatus == .authorizedWhenInUse {
locationManager.startUpdatingLocation()
} else {
locationManager.requestWhenInUseAuthorization()
}
}
func getLocationCoordinates() -> (Double, Double) {
let coordinate = self.locationManager.location != nil ? self.locationManager.location!.coordinate : CLLocationCoordinate2D()
print("location = \(coordinate.latitude), \(coordinate.longitude)")
return (Double(coordinate.latitude), Double(coordinate.longitude))
}
// Using closure
func getAddress(handler: @escaping (String) -> Void)
{
self.currentAddress = ""
let coordinate = self.locationManager.location != nil ? self.locationManager.location!.coordinate : CLLocationCoordinate2D()
let location = CLLocation(latitude: coordinate.latitude, longitude: coordinate.longitude)
let geoCoder = CLGeocoder()
geoCoder.reverseGeocodeLocation(location, completionHandler: { (placemarks, error) -> Void in
// Place details
var placeMark: CLPlacemark?
placeMark = placemarks?[0]
guard let placemark = placemarks?.first else { return }
if let streetNumber = placemark.subThoroughfare,
let street = placemark.subThoroughfare,
let city = placemark.locality,
let state = placemark.administrativeArea {
DispatchQueue.main.async {
self.currentAddress = "\(streetNumber) \(street) \(city) \(state)"
}
} else if let city = placemark.locality, let state = placemark.administrativeArea {
DispatchQueue.main.async {
self.currentAddress = "\(city) \(state)"
}
} else {
DispatchQueue.main.async {
self.currentAddress = "Address Unknown"
}
}
}
)
print( self.currentAddress)
}
}
extension LocationManager: CLLocationManagerDelegate {
func locationManagerDidChangeAuthorization(_ manager: CLLocationManager) {
if locationManager.authorizationStatus == .authorizedAlways || locationManager.authorizationStatus == .authorizedWhenInUse {
locationManager.startUpdatingLocation()
}
}
// MARK: - Get Placemark
func getPlace(for location: CLLocation,
completion: @escaping (CLPlacemark?) -> Void) {
let geocoder = CLGeocoder()
geocoder.reverseGeocodeLocation(location) { placemarks, error in
guard error == nil else {
print("*** Error in \(#function): \(error!.localizedDescription)")
completion(nil)
return
}
guard let placemark = placemarks?[0] else {
print("*** Error in \(#function): placemark is nil")
completion(nil)
return
}
completion(placemark)
}
}
}
1 ответ
Чтобы использовать следующий код, вам необходимо настроить соответствующие права и авторизации. Вот рабочий пример использования геолокации в swiftui из кода, который я получил из ряда источников в сети много лет назад. Это должно дать вам основу для обратной геолокации в swiftui:
import Foundation
import CoreLocation
import SwiftUI
import Combine
@main
struct TestApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
struct ContentView: View {
let locationProvider = LocationProvider()
@State var currentAddress = ""
var body: some View {
Text(currentAddress)
.onAppear {
getAddress()
}
}
func getAddress() {
// for testing Tokyo
let location = CLLocation(latitude: 35.684602, longitude: 139.751992)
locationProvider.getPlace(for: location) { plsmark in
guard let placemark = plsmark else { return }
if let streetNumber = placemark.subThoroughfare,
let street = placemark.subThoroughfare,
let city = placemark.locality,
let state = placemark.administrativeArea {
self.currentAddress = "\(streetNumber) \(street) \(city) \(state)"
} else if let city = placemark.locality, let state = placemark.administrativeArea {
self.currentAddress = "\(city) \(state)"
} else {
self.currentAddress = "Address Unknown"
}
}
}
}
/**
A Combine-based CoreLocation provider.
On every update of the device location from a wrapped `CLLocationManager`,
it provides the latest location as a published `CLLocation` object and
via a `PassthroughSubject<CLLocation, Never>` called `locationWillChange`.
*/
public class LocationProvider: NSObject, ObservableObject {
private let lm = CLLocationManager()
/// Is emitted when the `location` property changes.
public let locationWillChange = PassthroughSubject<CLLocation, Never>()
/**
The latest location provided by the `CLLocationManager`.
Updates of its value trigger both the `objectWillChange` and the `locationWillChange` PassthroughSubjects.
*/
@Published public private(set) var location: CLLocation? {
willSet {
locationWillChange.send(newValue ?? CLLocation())
}
}
/// The authorization status for CoreLocation.
@Published public var authorizationStatus: CLAuthorizationStatus?
/// A function that is executed when the `CLAuthorizationStatus` changes to `Denied`.
public var onAuthorizationStatusDenied : ()->Void = {presentLocationSettingsAlert()}
/// The LocationProvider intializer.
///
/// Creates a CLLocationManager delegate and sets the CLLocationManager properties.
public override init() {
super.init()
self.lm.delegate = self
self.lm.desiredAccuracy = kCLLocationAccuracyBest
self.lm.activityType = .fitness
self.lm.distanceFilter = 10
self.lm.allowsBackgroundLocationUpdates = true
self.lm.pausesLocationUpdatesAutomatically = false
self.lm.showsBackgroundLocationIndicator = true
}
/**
Request location access from user.
In case, the access has already been denied, execute the `onAuthorizationDenied` closure.
The default behavior is to present an alert that suggests going to the settings page.
*/
public func requestAuthorization() -> Void {
if self.authorizationStatus == CLAuthorizationStatus.denied {
onAuthorizationStatusDenied()
}
else {
self.lm.requestWhenInUseAuthorization()
}
}
/// Start the Location Provider.
public func start() throws -> Void {
self.requestAuthorization()
if let status = self.authorizationStatus {
guard status == .authorizedWhenInUse || status == .authorizedAlways else {
throw LocationProviderError.noAuthorization
}
}
else {
/// no authorization set by delegate yet
#if DEBUG
print(#function, "No location authorization status set by delegate yet. Try to start updates anyhow.")
#endif
/// In principle, this should throw an error.
/// However, this would prevent start() from running directly after the LocationProvider is initialized.
/// This is because the delegate method `didChangeAuthorization`,
/// setting `authorizationStatus` runs only after a brief delay after initialization.
//throw LocationProviderError.noAuthorization
}
self.lm.startUpdatingLocation()
}
/// Stop the Location Provider.
public func stop() -> Void {
self.lm.stopUpdatingLocation()
}
// todo deal with errors
public func getPlace(for location: CLLocation, completion: @escaping (CLPlacemark?) -> Void) {
let geocoder = CLGeocoder()
geocoder.reverseGeocodeLocation(location) { placemarks, error in
guard error == nil else {
print("=====> Error \(error!.localizedDescription)")
completion(nil)
return
}
guard let placemark = placemarks?.first else {
print("=====> Error placemark is nil")
completion(nil)
return
}
completion(placemark)
}
}
}
/// Present an alert that suggests to go to the app settings screen.
public func presentLocationSettingsAlert(alertText : String? = nil) -> Void {
let alertController = UIAlertController (title: "Enable Location Access", message: alertText ?? "The location access for this app is set to 'never'. Enable location access in the application settings. Go to Settings now?", preferredStyle: .alert)
let settingsAction = UIAlertAction(title: "Settings", style: .default) { (_) -> Void in
guard let settingsUrl = URL(string:UIApplication.openSettingsURLString) else {
return
}
UIApplication.shared.open(settingsUrl)
}
alertController.addAction(settingsAction)
let cancelAction = UIAlertAction(title: "Cancel", style: .default, handler: nil)
alertController.addAction(cancelAction)
UIApplication.shared.windows[0].rootViewController?.present(alertController, animated: true, completion: nil)
}
/// Error which is thrown for lacking localization authorization.
public enum LocationProviderError: Error {
case noAuthorization
}
extension LocationProvider: CLLocationManagerDelegate {
public func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
self.authorizationStatus = status
#if DEBUG
print(#function, status.name)
#endif
//print()
}
public func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
guard let location = locations.last else { return }
self.location = location
}
public func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
if let clErr = error as? CLError {
switch clErr {
case CLError.denied : do {
print(#function, "Location access denied by user.")
self.stop()
self.requestAuthorization()
}
case CLError.locationUnknown : print(#function, "Location manager is unable to retrieve a location.")
default: print(#function, "Location manager failed with unknown CoreLocation error.")
}
}
else {
print(#function, "Location manager failed with unknown error", error.localizedDescription)
}
}
}
extension CLAuthorizationStatus {
/// String representation of the CLAuthorizationStatus
var name: String {
switch self {
case .notDetermined: return "notDetermined"
case .authorizedWhenInUse: return "authorizedWhenInUse"
case .authorizedAlways: return "authorizedAlways"
case .restricted: return "restricted"
case .denied: return "denied"
default: return "unknown"
}
}
}