LocationService threading issues fixed on Android.

Author: David Britch

src/Mobile/eShopOnContainers/eShopOnContainers.Core/App.xaml.cs

@@ -79,7 +79,6 @@ private async Task GetGpsLocation()
                 try
                 {
                     var position = await locator.GetPositionAsync();
-
                     _settingsService.Latitude = position.Latitude.ToString();
                     _settingsService.Longitude = position.Longitude.ToString();
                 }

src/Mobile/eShopOnContainers/eShopOnContainers.Droid/Activities/MainActivity.cs

@@ -10,7 +10,6 @@
 using System;
 using Xamarin.Forms.Platform.Android;
 using eShopOnContainers.Droid.Services;
-using eShopOnContainers.Core.Services.Permissions;
 
 namespace eShopOnContainers.Droid.Activities
 {
@@ -21,8 +20,6 @@ namespace eShopOnContainers.Droid.Activities
         ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
     public class MainActivity : FormsAppCompatActivity
     {
-        public static IPermissionsService PermissionsService = new PermissionsService();
-
         protected override void OnCreate(Bundle bundle)
         {
             FormsAppCompatActivity.ToolbarResource = Resource.Layout.Toolbar;
@@ -60,7 +57,7 @@ public override void OnTrimMemory([GeneratedEnum] TrimMemory level)
         public override void OnRequestPermissionsResult(int requestCode, string[] permissions, Permission[] grantResults)
         {
             base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
-            ((PermissionsService)PermissionsService).OnRequestPermissionResult(requestCode, permissions, grantResults);
+            ((PermissionsService)PermissionsService.Current.Value).OnRequestPermissionResult(requestCode, permissions, grantResults);
         }
     }
 }

src/Mobile/eShopOnContainers/eShopOnContainers.Droid/Services/LocationServiceImplementation.cs

@@ -5,7 +5,6 @@
 using eShopOnContainers.Core.Models.Location;
 using eShopOnContainers.Core.Models.Permissions;
 using eShopOnContainers.Core.Services.Location;
-using eShopOnContainers.Droid.Activities;
 using eShopOnContainers.Droid.Services;
 using System;
 using System.Collections.Generic;
@@ -45,12 +44,12 @@ public LocationServiceImplementation()
 
         async Task<bool> CheckPermissionsAsync()
         {
-            var status = await MainActivity.PermissionsService.CheckPermissionStatusAsync(Permission.Location);
+            var status = await PermissionsService.Current.Value.CheckPermissionStatusAsync(Permission.Location);
             if (status != PermissionStatus.Granted)
             {
                 Console.WriteLine("Currently do not have Location permissions, requesting permissions.");
 
-                var request = await MainActivity.PermissionsService.RequestPermissionsAsync(Permission.Location);
+                var request = await PermissionsService.Current.Value.RequestPermissionsAsync(Permission.Location);
                 if (request[Permission.Location] != PermissionStatus.Granted)
                 {
                     Console.WriteLine("Location permission denied.");

src/Mobile/eShopOnContainers/eShopOnContainers.Droid/Services/PermissionsService.cs

@@ -8,6 +8,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace eShopOnContainers.Droid.Services
@@ -20,6 +21,8 @@ public class PermissionsService : IPermissionsService
         Dictionary<Permission, PermissionStatus> _results;
         IList<string> _requestedPermissions;
 
+        public static Lazy<IPermissionsService> Current = new Lazy<IPermissionsService>(() => new PermissionsService(), LazyThreadSafetyMode.PublicationOnly);
+
         #region Internal Implementation
 
         List<string> GetManifestNames(Permission permission)