Xamarin Forms Maps Geocoder Not Working on UWP Device - xamarin.forms

Question

My app uses Xamarin.Forms.Maps to display a map and also for geocoding. The map is displayed on a separate page when the user navigates to it from the main page. I use the geocoder to reverse geocode the current location so that I have the address. This is done from various places other than the map page.
When I run the app on a device (even in debug mode) the geocoder works right away in iOS and Android, but does not work in UWP. After I navigate to the map page and display the map, then go back to a different page to use the geocoder it starts working.
I saw a thread about the map not working with release build so I added the following code:
var laRendererAssemblies = new[] { typeof(Xamarin.Forms.Maps.UWP.MapRenderer).GetTypeInfo().Assembly };
Xamarin.Forms.Forms.Init(e, laRendererAssemblies);
//Xamarin.Forms.Forms.Init(e);
Xamarin.FormsMaps.Init("MyBingMapsKey");
This has not helped the issue with the Xamarin.Forms.Maps.Geocoder. I also tried creating an instance of Xamarin.Forms.Maps.Map in my main page, but that did not help either. Is there a way to prime the map component so that the Geocoder will work on a device? (My test device is ARM, but it happens when I run on Local
Machine (Win 10) too)
Following is a snippet of the call to the Geocoder (which works fine once the user has navigated to the Map page and back - and it works fine in iOS and Android - and as such I don't believe it is a problem with the code, but here it is):
public static async Task<Plugin.Geolocator.Abstractions.Position> Geocode(string address)
{
try
{
var loGeocoder = new Xamarin.Forms.Maps.Geocoder();
System.Diagnostics.Debug.WriteLine("Get Lat/Lon");
var lcolPositions = await loGeocoder.GetPositionsForAddressAsync(address);
if (lcolPositions != null)

Answer 1

After doing some research and ensuring that your geodecode class being static wouldn't mess with the async/await pattern in the UWP build. I've come across a few references to this particular problem with the built in Forms.Map geodecoder elsewhere, not just for UWP it has also been noted for android‡.
I took some time to have a look at one of our current cross-platform applications that we have in the app stores, and according to our internal documentation we switched out both the xamarin.forms map, and the geodecoder for custom ones.
The plugin that we use for our cross-platform application is the 'GelocatorPlugin' created by james montemagno, and can be found here.
It can be added to your project as a Nuget package if you prefer, and the implementation of it is very similar to the default one, so there's very little code to change. The primary benefit is that the UWP element of the geodecode plugin has been modified to take into account windows advanced tracking scenarios (details found here).
It should be a lot more stable than the one your using, once installed you simply use it like so:
Reverse Geocoding
Based on a location that is passed in, thi swill grab a list of
addresses.
UWP requires a Bing Map Key, which you can acquire by reading this
piece of documentation.
try
{
var addresses = await locator.GetAddressesForPositionAsync (position, string mapKey = null);
var address = addresses.FirstOrDefault();
if(address == null)
Console.WriteLine ("No address found for position.");
else
Console.WriteLine ("Addresss: {0} {1} {2}", address.Thoroughfare, address.Locality, address.Country);
}
catch(Exception ex)
{
Debug.WriteLine("Unable to get address: " + ex);
}
‡ Links to similar problems - Link 1, Link 2

Answer 2

resolved after added following lines in APP.xaml.cs (UWP project)
Xamarin.FormsMaps.Init("bingmapkey");
Windows.Services.Maps.MapService.ServiceToken = "bingmapkey";