Come recuperare il nome della città corrente dell'utente?

Come si recupera il nome della città corrente dell'utente?

Quello che devi fare è impostare un CLLocationManagerche troverà le tue coordinate correnti. Con le coordinate correnti che devi utilizzare MKReverseGeoCoderper trovare la tua posizione.

- (void)viewDidLoad 
{  
    // this creates the CCLocationManager that will find your current location
    CLLocationManager *locationManager = [[[CLLocationManager alloc] init] autorelease];
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters;
    [locationManager startUpdatingLocation];
}

// this delegate is called when the app successfully finds your current location
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation 
{
    // this creates a MKReverseGeocoder to find a placemark using the found coordinates
    MKReverseGeocoder *geoCoder = [[MKReverseGeocoder alloc] initWithCoordinate:newLocation.coordinate];
    geoCoder.delegate = self;
    [geoCoder start];
}

// this delegate method is called if an error occurs in locating your current location
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error 
{
 NSLog(@"locationManager:%@ didFailWithError:%@", manager, error);
}

// this delegate is called when the reverseGeocoder finds a placemark
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFindPlacemark:(MKPlacemark *)placemark
{
    MKPlacemark * myPlacemark = placemark;
    // with the placemark you can now retrieve the city name
    NSString *city = [myPlacemark.addressDictionary objectForKey:(NSString*) kABPersonAddressCityKey];
}

// this delegate is called when the reversegeocoder fails to find a placemark
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFailWithError:(NSError *)error
{
    NSLog(@"reverseGeocoder:%@ didFailWithError:%@", geocoder, error);
}

A partire da iOS 5 MKReverseGeoCoderè deprecato!

Quindi vuoi usare CLGeocodercon CLLocationManager, molto semplice e funziona con il blocco.

Esempio:

- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation
{
   [self.locationManager stopUpdatingLocation];

   CLGeocoder * geoCoder = [[CLGeocoder alloc] init];
    [geoCoder reverseGeocodeLocation:newLocation
                   completionHandler:^(NSArray *placemarks, NSError *error) {
                       for (CLPlacemark *placemark in placemarks) {
                           .... = [placemark locality];
                       }
                   }];
}

Modifica: invece di un for inciclo puoi anche fare:

NSString *locString = placemarks.count ? [placemarks.firstObject locality] : @"Not Found";

Questo funziona bene per me:

CLGeocoder *geocoder = [[CLGeocoder alloc] init] ;
[geocoder reverseGeocodeLocation:self.locationManager.location
               completionHandler:^(NSArray *placemarks, NSError *error) {
                   NSLog(@"reverseGeocodeLocation:completionHandler: Completion Handler called!");

                   if (error){
                       NSLog(@"Geocode failed with error: %@", error);
                       return;

                   }


                   CLPlacemark *placemark = [placemarks objectAtIndex:0];

                   NSLog(@"placemark.ISOcountryCode %@",placemark.ISOcountryCode);
                   NSLog(@"placemark.country %@",placemark.country);
                   NSLog(@"placemark.postalCode %@",placemark.postalCode);
                   NSLog(@"placemark.administrativeArea %@",placemark.administrativeArea);
                   NSLog(@"placemark.locality %@",placemark.locality);
                   NSLog(@"placemark.subLocality %@",placemark.subLocality);
                   NSLog(@"placemark.subThoroughfare %@",placemark.subThoroughfare);

               }];

Se qualcuno sta cercando di passare a CLGeocoder da MKReverseGeocoder, ho scritto un post sul blog che potrebbe essere di aiuto http://jonathanfield.me/jons-blog/clgeocoder-example.html

Fondamentalmente un esempio potrebbe essere, dopo aver creato gli oggetti locationManager e CLGeocoder, aggiungi semplicemente questo codice a viewDidLoad () e quindi crea alcune etichette o aree di testo per mostrare i dati.

  [super viewDidLoad];
    locationManager.delegate = self;
    [locationManager startUpdatingLocation];

    locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
    [self.CLGeocoder reverseGeocodeLocation: locationManager.location completionHandler: 
     ^(NSArray *placemarks, NSError *error) {


         CLPlacemark *placemark = [placemarks objectAtIndex:0];


             isoCountryCode.text = placemark.ISOcountryCode;
             country.text = placemark.country;
             postalCode.text= placemark.postalCode;
             adminArea.text=placemark.administrativeArea;
             subAdminArea.text=placemark.subAdministrativeArea;
             locality.text=placemark.locality;
             subLocality.text=placemark.subLocality;
             thoroughfare.text=placemark.thoroughfare;
             subThoroughfare.text=placemark.subThoroughfare;
             //region.text=placemark.region;



     }];

Se qualcuno ne ha bisogno in Swift 3 , è così che l'ho fatto:

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

    let location = locations.first!
    let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate, 500, 500)

    self.location = location
    self.locationManager?.stopUpdatingLocation()

    // Drop a pin at user's Current Location
    let myAnnotation: MKPointAnnotation = CustomPointAnnotation()
    myAnnotation.coordinate = CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude)
    myAnnotation.title = "Localização"
    self.mapViewMK.addAnnotation(myAnnotation)

    self.mapViewMK.setRegion(coordinateRegion, animated: true)
    self.locationManager?.stopUpdatingLocation()
    self.locationManager = nil

    // Get user's current location name
    let geocoder = CLGeocoder()
    geocoder.reverseGeocodeLocation(self.location!) { (placemarksArray, error) in

        if (placemarksArray?.count)! > 0 {

            let placemark = placemarksArray?.first
            let number = placemark!.subThoroughfare
            let bairro = placemark!.subLocality
            let street = placemark!.thoroughfare

            self.addressLabel.text = "\(street!), \(number!) - \(bairro!)"
        }
    }
}

Dopo aver configurato CLLocationManager, riceverai l'aggiornamento della posizione come coppia latitudine / longitudine. Quindi è possibile utilizzare CLGeocoder per convertire le coordinate in un nome di luogo facile da usare.

Ecco il codice di esempio in Swift 4 .

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    if let lastLocation = locations.last {
        let geocoder = CLGeocoder()

        geocoder.reverseGeocodeLocation(lastLocation) { [weak self] (placemarks, error) in
            if error == nil {
                if let firstLocation = placemarks?[0],
                    let cityName = firstLocation.locality { // get the city name
                    self?.locationManager.stopUpdatingLocation()
                }
            }
        }
    }
}

Devi ottenere la posizione corrente dell'utente e quindi utilizzare MKReverseGeocoder per riconoscere la città.

C'è un ottimo esempio nella Guida alla programmazione delle app per iPhone , capitolo 8. Dopo aver inizializzato la posizione del geocoder, impostare il delegato e leggere il paese dal segnaposto. Leggi la documentazione per MKReverseGeocodeDelegate e crea metodi:

• reverseGeocoder: didFindPlacemark:

• reverseGeocoder: didFailWithError:

  MKReverseGeocoder *geocoder = [[MKReverseGeocoder alloc] initWithCoordinate:newLocation.coordinate];
  geocoder.delegate = self;
  [geocoder start];

Puoi utilizzare questo codice per ottenere la città corrente: -

extension YourController: CLLocationManagerDelegate {func locationManager (manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

    CLGeocoder().reverseGeocodeLocation(manager.location!, completionHandler: {(placemarks, error)->Void in

        if (error != nil)
        {
            manager.stopUpdatingLocation()
            return
        }
        else
        {
            if placemarks!.count > 0
            {
                let placeMarksArrray: NSArray = placemarks!
                let pm = placeMarksArrray[0] as! CLPlacemark
                self.displayLocationInfo(pm)
                manager.stopUpdatingLocation()
            } else
            {
                print("Problem with the data received from geocoder")
            }
        }
    })
}

func displayLocationInfo(placemark: CLPlacemark!) {
    if (placemark != nil) {
        //stop updating location to save battery life
        locationLocation.stopUpdatingLocation()
        var tempString : String = ""
        if(placemark.locality != nil){
            tempString = tempString +  placemark.locality! + " "
            print(placemark.locality)
        }
        if(placemark.postalCode != nil){
            tempString = tempString +  placemark.postalCode! + " "
            print(placemark.postalCode)
        }
        if(placemark.administrativeArea != nil){
            tempString = tempString +  placemark.administrativeArea! + " "
            print(placemark.administrativeArea)
        }
        if(placemark.country != nil){
            tempString = tempString +  placemark.country! + " "



        }
        let dictForaddress = placemark.addressDictionary as! NSDictionary


        if let city = dictForaddress["City"] {
            print(city)



        }
        strLocation = tempString
    }
}

// place the function code below in desire location in program.

// [self getCurrentLocation];



-(void)getCurrentLocation
{
    CLGeocoder *geocoder = [[CLGeocoder alloc] init] ;
    [geocoder reverseGeocodeLocation:self->locationManager.location
                   completionHandler:^(NSArray *placemarks, NSError *error) {
                       NSLog(@"reverseGeocodeLocation:completionHandler: Completion Handler called!");

                       if (error){
                           NSLog(@"Geocode failed with error: %@", error);
                           return;

                       }


                       CLPlacemark *placemark = [placemarks objectAtIndex:0];

                       NSLog(@"placemark.ISOcountryCode %@",placemark.ISOcountryCode);
                       NSLog(@"placemark.country %@",placemark.country);
                        NSLog(@"placemark.locality %@",placemark.locality );
                       NSLog(@"placemark.postalCode %@",placemark.postalCode);
                       NSLog(@"placemark.administrativeArea %@",placemark.administrativeArea);
                       NSLog(@"placemark.locality %@",placemark.locality);
                       NSLog(@"placemark.subLocality %@",placemark.subLocality);
                       NSLog(@"placemark.subThoroughfare %@",placemark.subThoroughfare);

                   }];
}

Ecco la mia piccola classe Swift che mi aiuta a ottenere informazioni geocodificate inverse sulla posizione corrente. Non dimenticare il NSLocationWhenInUseUsageDescriptioncampo in Info.plist.

class CurrentPlacemarkUpdater: NSObject, CLLocationManagerDelegate {

    private let locationManager = CLLocationManager()
    private let geocoder = CLGeocoder()

    private(set) var latestPlacemark: CLPlacemark?
    var onLatestPlacemarkUpdate: (() -> ())?
    var shouldStopOnUpdate: Bool = true

    func start() {
        locationManager.requestWhenInUseAuthorization()
        locationManager.desiredAccuracy = kCLLocationAccuracyKilometer
        locationManager.delegate = self
        locationManager.startUpdatingLocation()
    }

    func stop() {
        locationManager.stopUpdatingLocation()
    }

    fileprivate func updatePlacemark(for location: CLLocation) {
        geocoder.reverseGeocodeLocation(location) { [weak self] placemarks, error in
            if let placemark = placemarks?.first {
                self?.latestPlacemark = placemark
                self?.onLatestPlacemarkUpdate?()
                if self?.shouldStopOnUpdate ?? false {
                    self?.stop()
                }
            }
        }
    }

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        if let location = locations.last {
            updatePlacemark(for: location)
        }
    }

    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
        print("CurrentPlacemarkUpdater: \(error)")
    }

}

Leggi la documentazione per MKReverseGeocoder : la documentazione, le guide e le applicazioni di esempio sono fornite da Apple per un motivo.