Get user location when app runs and re-center again after moving around using a button - ios

Question

I'm working on a project about MapKit using Swift 3. What the code below does is once I load the app the map will load in default. Then when the user presses the button it takes you to the user's location.
The way I want to fix this is I want it to load the user's location as soon as the app runs, and then when the user decides to move around the screen, she/he could hit the button and then recenter the user location again. Like how it works on Maps.
import UIKit
import MapKit
import CoreLocation
class ViewController: UIViewController, CLLocationManagerDelegate {
// connecting the map from the mainBoard and refering to it as "myMap".....
#IBOutlet weak var myMap: MKMapView!
#IBAction func refLocation(_ sender: Any) {
manager.startUpdatingLocation()
}
let manager = CLLocationManager()
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
if let location = locations.last {
let span: MKCoordinateSpan = MKCoordinateSpanMake(0.0075,0.0075)
let myLocation :CLLocationCoordinate2D = CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude)
let region: MKCoordinateRegion = MKCoordinateRegionMake(myLocation, span)
myMap.setRegion(region, animated: true)
}
self.myMap.showsUserLocation = true
manager.stopUpdatingLocation()
}
override func viewDidLoad() {
super.viewDidLoad()
manager.delegate = self
manager.desiredAccuracy = kCLLocationAccuracyBest
manager.requestWhenInUseAuthorization()
}
}

Answer 1

It isn't clear what you're asking.
If you want to get a single location update you can use the function func requestLocation().
You could create a location manager (and set yourself as its delegate) in your view controller's viewDidLoad and call requestLocation() once.
Then call requestLocation() again in your button action.
Make your didUpdateLocations method always recenter the map. That way you'll receive one and only one update from clicking your button, and the map will recenter as soon as the update is received.

Answer 2

Try this code for Swift 3
import UIKit
import MapKit
import CoreLocation
class ViewController2: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {
var locationManager = CLLocationManager()
var currentLocation = CLLocation()
var currentLat: Double!
var currentLon: Double!
#IBOutlet weak var mapView: MKMapView!
override func viewDidLoad() {
super.viewDidLoad()
myLocation()
}
func myLocation()
{
if currentLocation.coordinate.latitude == 0.00 || currentLocation.coordinate.longitude == 0.0
{
print("no location")
}
else
{
self.locationManager.requestWhenInUseAuthorization()
if CLLocationManager.locationServicesEnabled()
{
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
}
let locManager = CLLocationManager()
locManager.requestWhenInUseAuthorization()
if(CLLocationManager.authorizationStatus() == CLAuthorizationStatus.authorizedWhenInUse ||
CLLocationManager.authorizationStatus() == CLAuthorizationStatus.authorizedAlways)
{
currentLocation = locManager.location!
}
print("currentLongitude: \(currentLocation.coordinate.longitude)")
print("currentLatitude: \(currentLocation.coordinate.latitude)")
currentLon = currentLocation.coordinate.longitude
currentLat = currentLocation.coordinate.latitude
let span = MKCoordinateSpanMake(0.2, 0.2)
let region = MKCoordinateRegion(center: CLLocationCoordinate2D(latitude: currentLat, longitude: currentLon), span: span)
mapView.setRegion(region, animated: true)
}
}
#IBAction func MyLocationBtnPressed(_ sender: Any)
{
let span = MKCoordinateSpanMake(0.1, 0.1)
let region = MKCoordinateRegion(center: CLLocationCoordinate2D(latitude: currentLat, longitude: currentLon), span: span)
mapView.setRegion(region, animated: true)
}
}

Answer 3

You don't have to call startUpdatingLocation() again because MapView always knows userLocation.
Replace
#IBAction func refLocation(_ sender: Any) {
manager.startUpdatingLocation()
}
with
#IBAction func refLocation(_ sender: Any) {
let region: MKCoordinateRegion = MKCoordinateRegionMake(myMap.userLocation.coordinate, myMap.region.span)
mapView.setRegion(region, animated: true)
}