In Xamarin How to get device location to use in Google Maps routes

Question

I'm trying to use some kind of deep link to from my app, open google maps with a route to follow. I'm using Xamarin portable, and I'm using this code, that is working, but is keeping the starting postion of the route, blank.

var latDestiny = ClientMap.Latitude.ToString().Replace(",", ".");
var longiDestiny = ClientMap.Longitude.ToString().Replace(",", ".");

string destiny = "&destination=" + latDestino + "," + longiDestino;

var gMapsURL = "https://www.google.com/maps/dir/?api=1" + destiny;
GlobalLib.OpenExternalURL(gMapsURL);

I saw that i need to add something like this to the link:

"&origin=" + myLatitude + "," + myLongitude;

but all the ways I find to get the device postion are not clear and looks very complicated, does someone have a good solution to find the device latitude and longigute?

Answer 1

Try this idea: (I use in my app and it works nice)

Create an Interface in the portable project: (yes, you will need to treat the current location differently in each platform)

namespace YourProject
{
    public interface ILibNative
    {                
        Position ReturnDevicePosition();
    }
}

then, create a class that derives the interface inside iOS and Android projects: ANDROID:

[assembly: Dependency(typeof(LibNative_DROID))]
namespace YourProject.Droid
{
    public class LibNative_DROID : ILibNative
    {

        public LibNative_DROID()
        {
        }

        public Position ReturnDevicePosition()
        {
            Position myPosition = new Position();
            try
            {
                Accuracy DesiredAccuracy = Accuracy.Fine;
                var locationManager = (LocationManager)Android.App.Application.Context.GetSystemService(Context.LocationService);
                if (locationManager.AllProviders.Count > 0)
                {
                    var criteria = new Criteria
                    {
                        Accuracy = DesiredAccuracy
                    };

                    var provider = locationManager.GetBestProvider(criteria, true);

                    myPosition = new Position(locationManager.GetLastKnownLocation(provider).Latitude, locationManager.GetLastKnownLocation(provider).Longitude);
                }
                return myPosition;
            }
            catch
            {
                return myPosition;
            }
        }
    }
}

iOS:

[assembly: Dependency(typeof(LibNative_iOS))]
namespace YourProject.iOS
{
    public class LibNative_iOS : ILibNative
    {

        public LibNative_iOS()
        {
        }              

        public Position ReturnDevicePosition()
        {
            Position myPosition = new Position();
            try
            {
                if (CLLocationManager.LocationServicesEnabled)
                {
                    CLLocationManager locationManager = new CLLocationManager();
                    locationManager.RequestWhenInUseAuthorization();
                    var location = locationManager.Location;
                    myPosition = new Position(location.Coordinate.Latitude, location.Coordinate.Longitude);
                }
                return myPosition;
            }
            catch
            {
                return myPosition;
            }
        }
    }
}

Don't forget to ask for enabled access to your location in the manifests (fine_location, coarse_location, gps, internet, etc...)

then, after did that, you can do this:

var MyPosition = new Position();
MyPosition = DependencyService.Get<ILibNative>().ReturnDevicePosition(); 
var myLatitude = MyPosition.Latitude.ToString().Replace(",", ".");
var myLongitude = MyPosition.Longitude.ToString().Replace(",", ".");
string startingPoint = "&origin=" + myLatitude + "," + myLongitude;

Now, just add 'startingPoint' to your googleMaps URL...