Don't know how to open the Map in SwiftUI (Xcode 12.4)

Question

I just started programming in Xcode and some things still seem kinda difficult for me to understand. I found a tutorial with code on medium.com to implement the current user location with MapKit. The code to get the user location and display this on the map is written in the MapViewController.swift file & class, which can be seen below.

import Foundation
import UIKit
import MapKit
import CoreLocation

class MapViewController: UIViewController, CLLocationManagerDelegate {
    
    let mapView = MKMapView()
    let locationManager = CLLocationManager()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupMapView()
        checkLocationServices()
        // Do any additional setup after loading the view.
    }
    
    func setupMapView() {
        view.addSubview(mapView)
        mapView.translatesAutoresizingMaskIntoConstraints = false
        mapView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        mapView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
        mapView.rightAnchor.constraint(equalTo: view.safeAreaLayoutGuide.rightAnchor).isActive = true
        mapView.leftAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leftAnchor).isActive = true 
    }
    
    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        guard let location = locations.last else { return }
        let region = MKCoordinateRegion.init(center: location.coordinate, latitudinalMeters: 4000, longitudinalMeters: 4000)
        mapView.setRegion(region, animated: true)
    }
    
    func checkLocalAuthorization() {
        switch CLLocationManager.authorizationStatus() {
        case .authorizedWhenInUse:
            mapView.showsUserLocation = true
            followUserLocation()
            locationManager.startUpdatingLocation()
            break
        case .denied:
            // Show alert
            break
        case .notDetermined:
            locationManager.requestWhenInUseAuthorization()
        case .restricted:
            // Show alert
            break
        case .authorizedAlways:
            break
        @unknown default:
        fatalError()
        }
    }
    
    func checkLocationServices() {
        if CLLocationManager.locationServicesEnabled() {
            setupLocationManager()
            checkLocalAuthorization()
        } else {
            // user did not turn it on
        }
    }
    
    func followUserLocation() {
        if let location = locationManager.location?.coordinate {
            let region = MKCoordinateRegion.init(center: location, latitudinalMeters: 4000, longitudinalMeters: 4000)
            mapView.setRegion(region, animated: true)
        }
    }
    
    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        checkLocalAuthorization()
    }
    
    func setupLocationManager() {
        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
    }

}

The problem is that I don't know how to run the code so that the map is visible. When I call the MapViewController() class in ContentView.swift like below, I get the errors "Return type of property 'body' requires that 'MapViewController' conform to 'View'" and "Static method 'buildBlock' requires that 'MapViewController' conform to 'View'". Can someone please explain how I can fix the error and just see the map? Thanks a lot in advance

import SwiftUI
import UIKit
import CoreLocation
import MapKit

struct ContentView: View {
var body: some View {
    MapViewController()
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

user_11878069 · Answer

You will need a UIViewControllerRepresentable:

struct MapViewRepresentable: UIViewControllerRepresentable {
    func makeUIViewController(context: Context) -> some UIViewController {
        return MapViewController()
    }
    
    func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
    }
}


struct ContentView: View {
    var body: some View {
        MapViewRepresentable() //<< here use your UIViewControllerRepresentable
    }
}

Don't know how to open the Map in SwiftUI (Xcode 12.4)

1 Answers