startMonitoringSignificantLocationChanges Does not work in background

Question

I’m making an app that uses the device’s location service. It necessarily needs to be capturing the positions when there is a change of location and should capture in all situations (background/foreground/Killed), so I’m using the method startMonitoringSignificantLocationChanges(), But when I send it to the background, the capture of positions only runs for a while longer and stops, after that no longer captures. I get around the distance that the documentation suggests to update (500m) position and nothing happens. What could I be doing wrong? Note: The simulator works perfectly, but the physical device does not work.

The archive Info.plist. is with background configuration enabled

<key>UIBackgroundModes</key>
  <array>
    <string>fetch</string>
    <string>location</string>
  </array>

Appdelegate.Swift

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    if (launchOptions != nil) {
        let locationManager = CLLocationManager()
        locationManager.delegate = ViewController()
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        locationManager.activityType = CLActivityType.other
        locationManager.allowsBackgroundLocationUpdates = true
        locationManager.startUpdatingLocation()
    }

    return true
}

func applicationDidEnterBackground(_ application: UIApplication) {
    let locationManager = CLLocationManager()
    locationManager.delegate = ViewController()
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.activityType = CLActivityType.other
    locationManager.allowsBackgroundLocationUpdates = true
    locationManager.startMonitoringSignificantLocationChanges()
}

Viewcontroller.Swift

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {    
    //Trato a captura da nova localização 
}

Answer 1

Two suggestions...

I noticed that, in the code sent, you are not asking for permission to pick up the user’s location... Maybe this is a problem. To resolve this, just put in viewDidLoad: locationManager.requestWhenInUseAuthorization()

Another possibility is that the documentation states that this function does not send repeated notifications in less than 5 minutes. That is, even if you move more than 500 meters, if not already 5 minutes past the last notification, the app will not notify you again until they pass these 5 minutes.

If you need to check the user’s location changes more often than that, I think you’ll have to use startUpdatingLocation() and calculate if the user has moved enough or not...