CODEWITHSUNDEEP
iosbackgroundxamaringeolocationlocation
Jared Price
Jared Price

Reputation: 5375

Xamarin iOS - CLLocationManager get location at set time interval while in background

I'm trying to add a feature to my application that requires obtaining the user's currently location at a set time interval. The issue is that whenever I use System.Threading.Timer, create a new System.Threading.Thread and use Thread.Sleep(), or use NSTimer.CreateScheduledTimer the application will stop the CLLocationManager from running when the application is in the background.

LocationManager.cs

public class LocationManager
{
    protected CLLocationManager locationManager;
    /// <summary>
    /// Time in milliseconds between location checking.
    /// </summary>
    private int serviceMillisecondTimeout = 10000;

    public LocationManager()
    {
        this.locationManager = new CLLocationManager();

        // iOS 8 additional permissions requirements
        if (UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
        {
            locationManager.RequestAlwaysAuthorization();
        }

        locationManager.LocationsUpdated += onLocationUpdated;
        locationManager.DistanceFilter = 1;
        locationManager.DesiredAccuracy = 1;
    }

    public CLLocationManager LManager
    {
        get { return locationManager; }
    }

    public void startLocationUpdates()
    {
        if (CLLocationManager.LocationServicesEnabled)
        {
            locationManager.StartUpdatingLocation();
        }
    }

    public void stopLocationUpdates()
    {
        locationManager.StopUpdatingLocation();
    }

    public void onLocationUpdated(object sender, CLLocationsUpdatedEventArgs e)
    {
        // stop location updates until timer calls StartUpdatingLocation
        locationManager.StopUpdatingLocation();

        var coordinate = e.Locations[e.Locations.Length - 1].Coordinate;
        double lat = coordinate.Latitude;
        double lon = coordinate.Longitude;

        // do stuff with coordinates

        // This will work until the application goes into the background.
        // The same thing seems to happen whenever I try creating
        // new threads, or any other form of a timer.
        //
        // Without any sort of timer or new thread, it will call
        // StartUpdatingLocation in the background and will
        // continue to run indefinitely.
        NSTimer t = NSTimer.CreateScheduledTimer(TimeSpan.FromMilliseconds(serviceMillisecondTimeout), delegate
        {
            if (CLLocationManager.LocationServicesEnabled)
            {
                locationManager.StartUpdatingLocation();
            }
        });
    }
}

What can I do to set an explicit time interval and still be able to run location updates in the background?

Upvotes: 2

Views: 1667

Answers (1)

der_michael
der_michael

Reputation: 3362

This functionality would not be supported by the platform. You can subscribe to significant location changes when in the background or leaving a set geofence but you can not force your code to get a location fix at a specific interval in the background. This is a restriction/limitation of the iOS platform and there is nothing you can do about it.

The closest thing to what you want is maybe Getting Location Events in the Background.

Upvotes: 1

Related Questions