Swift programming: Multiple Positions on Map View - swift

Question

I have a simple problem and I am new to IOS - I want to have multiple GPS streams coming on the same map. Please help as to how could that be done
the current code works:
import UIKit
import MapKit
import CoreLocation
class ViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {
#IBOutlet weak var mapView: MKMapView!
let locationManager = CLLocationManager()
override func viewDidLoad()
{
super.viewDidLoad()
self.locationManager.delegate = self
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.requestWhenInUseAuthorization()
self.locationManager.startUpdatingLocation()
self.mapView.showsUserLocation = true
self.mapView.delegate = self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func locationmanager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation])
{
let location = locations.last
let center = CLLocationCoordinate2D(latitude: location!.coordinate.latitude, longitude: location!.coordinate.longitude)
let region = MKCoordinateRegion(center: center, span: MKCoordinateSpan(latitudeDelta: 0.01, longitudeDelta: 0.01))
self.mapView.setRegion(region, animated: true)
self.locationManager.stopUpdatingLocation()
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError)
{
print("Errors: " + error.localizedDescription)
}
}
but this only gives me one location.

Answer 1

You have a map displayed, and on that map you want to display two locations.
The first location is that of the device, so you get the co-ordinates from the device's GPS.
The second location is somebody else's position. Where are you getting their co-ordinates from? You cannot access their GPS. The app on their device must write their co-ordinates to a server somewhere. You app then reads these co-ordinates from the server and displays them using a MKPointAnnotation. There is no "GPS stream" for the app other than that for the device it is running on.
Similarly, the app on your device must write your own co-ordinates, so it can appear on their app.
If you don't have a server, you could investigate using Apple's CloudKit (for example).