Merge pull request Azure-Samples#493 from Azure-Samples/VJTest

Fix for intermittent crash when creating ExtendedExecutionSessoin to …
romitgirdhar · Apr 11, 2016 · 54723a6 · 54723a6
2 parents a6d54f1 + 218855f
commit 54723a6
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Showing 2 changed files with 35 additions and 21 deletions.
diff --git a/src/MobileApps/MyDriving/MyDriving.UWP/MyDriving.UWP.csproj b/src/MobileApps/MyDriving/MyDriving.UWP/MyDriving.UWP.csproj
@@ -400,7 +400,7 @@
     <SDKReference Include="Microsoft.VCLibs, Version=14.0">
       <Name>Visual C++ 2015 Runtime for Universal Windows Platform Apps</Name>
     </SDKReference>
-    <SDKReference Include="SQLite.UWP.2015, Version=3.11.1">
+    <SDKReference Include="SQLite.UWP.2015, Version=3.12.0">
       <Name>SQLite for Universal Windows Platform</Name>
     </SDKReference>
   </ItemGroup>

diff --git a/src/MobileApps/MyDriving/MyDriving.UWP/Views/CurrentTripView.xaml.cs b/src/MobileApps/MyDriving/MyDriving.UWP/Views/CurrentTripView.xaml.cs
@@ -184,28 +184,38 @@ private async Task BeginExtendedExecution()
 
             ClearExtendedExecution();
 
-            var newSession = new ExtendedExecutionSession
+            try
             {
-                Reason = ExtendedExecutionReason.LocationTracking,
-                Description = "Tracking your location"
-            };
-            newSession.Revoked += SessionRevoked;
-            ExtendedExecutionResult result = await newSession.RequestExtensionAsync();
-            switch (result)
-            {
-                case ExtendedExecutionResult.Allowed:
-                    session = newSession;
-                    ViewModel.Geolocator.AllowsBackgroundUpdates = true;
-                    ViewModel.StartTrackingTripCommand.Execute(null);
+                var newSession = new ExtendedExecutionSession
+                {
+                    Reason = ExtendedExecutionReason.LocationTracking,
+                    Description = "Tracking your location"
+                };
+                newSession.Revoked += SessionRevoked;
+                ExtendedExecutionResult result = await newSession.RequestExtensionAsync();
+                switch (result)
+                {
+                    case ExtendedExecutionResult.Allowed:
+                        session = newSession;
+                        ViewModel.Geolocator.AllowsBackgroundUpdates = true;
+                        ViewModel.StartTrackingTripCommand.Execute(null);
 
-                    break;
+                        break;
 
-                default:
-                    Acr.UserDialogs.UserDialogs.Instance.Alert("Unable to execute app in the background.",
-                      "Background execution denied.", "OK");
+                    default:
+                        Acr.UserDialogs.UserDialogs.Instance.Alert("Unable to execute app in the background.",
+                          "Background execution denied.", "OK");
 
-                    newSession.Dispose();
-                    break;
+                        newSession.Dispose();
+                        break;
+                }
+            }
+            catch (Exception ex)
+            {
+                // Sometimes while creating ExtendedExecution session you get Resource not ready exception. 
+                Logger.Instance.Report(ex);
+                Acr.UserDialogs.UserDialogs.Instance.Alert("Will not be able to execute app in the background.",
+                        "Background execution session failed.", "OK");
             }
         }
 
@@ -371,7 +381,7 @@ await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
 
         private async void DrawPath(BasicGeoposition basicGeoposition)
         {
-            if (!ViewModel.IsRecording || ViewModel.CurrentTrip.Points.Count == 0)
+            if (!ViewModel.IsRecording || ViewModel.CurrentTrip?.Points?.Count == 0)
                 return;
 
             await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
@@ -383,8 +393,12 @@ await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
                 {
                 Locations =
                     new List<BasicGeoposition>(
-                        ViewModel.CurrentTrip.Points.Select(
+                        ViewModel.CurrentTrip?.Points?.Select(
                             s => new BasicGeoposition() { Latitude = s.Latitude, Longitude = s.Longitude }));
+
+                    // If the viewmodel still has not added this point, then add it locally to the Locations collection.
+                    if (Locations.Count == 0)
+                        Locations.Add(basicGeoposition);
                 }
                 else
                     Locations.Add(basicGeoposition);