Xamarin.Android - How to continue a process while app is minimized or screen is locked - asynchronous

Question

I've created a Xamarin app that checks the users current location every couple minutes. My problem is it doesn't work when I minimize the app or the screen locks. Is there a way for me to continue the process while minimized or when the phone is locked?
This function checks to see if the user is at the destination location.
public bool atLocation(decimal currentLat, decimal currentLong, decimal destLat, decimal destLong)
{
decimal GPSLatitudePadding = 0.001M;
decimal GPSLongitudePadding = 0.001M;
var totalLowerLatitude = Convert.ToDecimal((destLat - GPSLatitudePadding).ToString("#.####"));
var totalLowerLongitude = Convert.ToDecimal((destLong + GPSLongitudePadding).ToString("#.####"));
var totalUpperLatitude = Convert.ToDecimal((destLat + GPSLatitudePadding).ToString("#.####"));
var totalUpperLongitude = Convert.ToDecimal((destLong - GPSLongitudePadding).ToString("#.####"));
if ((Convert.ToDecimal(destLat) >= totalLowerLatitude) &&
(Convert.ToDecimal(destLat) <= totalUpperLatitude) &&
(Convert.ToDecimal(destLong) <= totalLowerLongitude) &&
(Convert.ToDecimal(destLong) >= totalUpperLongitude))
{
return true;
}
return false;
}
If the user is at the destination for 2 instances of 2 minutes the process is ended. This is where you could start a new process or update a database.
int intNumberOfTimesFoundAtLocation = 0;
void OnLocationResult(object sender, Android.Locations.Location location)
{
decimal currentLatitude = Convert.ToDecimal(location.Latitude);
decimal currentLongitude = Convert.ToDecimal(location.Longitude);
decimal destLatitude = Convert.ToDecimal(this.dblDestLatitude);
decimal destLongitude = Convert.ToDecimal(this.dblDestLongitude);
var atLocation = locationQ.atLocation(currentLatitude, currentLongitude, destLatitude, destLongitude);
if (ayLocation == true)
{
intNumberOfTimesFoundAtLocation = intNumberOfTimesFoundAtLocation + 1;
if(intNumberOfTimesFoundAtLocation == 2)
{
client.RemoveLocationUpdates(locationCallback);
}
}
}
I call this function to start the process
MyLocationCallback locationCallback;
FusedLocationProviderClient client;
public async void StartLocationUpdatesAsync()
{
// Create a callback that will get the location updates
if (locationCallback == null)
{
locationCallback = new MyLocationCallback();
locationCallback.LocationUpdated += OnLocationResult;
}
// Get the current client
if (client == null)
client = LocationServices.GetFusedLocationProviderClient(this);
try
{
locationRequest = new LocationRequest()
.SetInterval(120000)
.SetFastestInterval(120000)
.SetPriority(LocationRequest.PriorityHighAccuracy);
await client.RequestLocationUpdatesAsync(locationRequest, locationCallback);
}
catch (Exception ex)
{
//Handle exception here if failed to register
}
}
}
class MyLocationCallback : LocationCallback
{
public EventHandler<Android.Locations.Location> LocationUpdated;
public override void OnLocationResult(LocationResult result)
{
base.OnLocationResult(result);
LocationUpdated?.Invoke(this, result.LastLocation);
}
}

Answer 1

Create a foreground service.
Inside service call the following code to start the request updates.
locationLogger = new LocationLogger();
locationLogger.LogInterval = _currentInterval;
locationLogger.StopUpdates();
locationLogger.StartRequestionUpdates();
Check here for the code
Let me know if you need more help.