Google map Geocoder And MoveToRegion not working - google-maps

Question

I' have a very strange issue with Xamarin.Forms.Maps.
I'm trying to implement a page with a map that get current location and move to region at page start.
All is working fine in IOS, but in Android, Geocoder & MoveToRegion are not working at all. Only the map is displayed.
I retrieve the location correctly (Long & Lat ) in the emulators & device.
MoveToRegion do nothing & GetAddressesForPositionAsync retrive nothing.
Here the information in my manifest :
<meta-data android:name="com.google.android.maps.v2.API_KEY" android:value="mykey" />
<meta-data android:name="com.google.android.gms.version" android:value="#integer/google_play_services_version" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
Here the code :
map.MoveToRegion(MapSpan.FromCenterAndRadius(
new Xamarin.Forms.Maps.Position(coordinates.Lat.Value, coordinates.Lng.Value), Distance.FromMiles(1))
);
var possibleAddresses = await locator.GetAddressesForPositionAsync(position);
I tried in Genymotion, Emulator from AVD.
I'm not able to test in real device ( The deployment fail in my tablet )
Edit :
global::Xamarin.Forms.Forms.Init(this, bundle);
Was correctly set but still not working.
I force geocoder usage and it thrown this error :
[MonoDroid] UNHANDLED EXCEPTION:
[MonoDroid] Java.IO.IOException: grpc failed
[MonoDroid] at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at Java.Interop.JniEnvironment+InstanceMethods.CallObjectMethod (Java.Interop.JniObjectReference instance, Java.Interop.JniMethodInfo method, Java.Interop.JniArgumentValue* args) [0x00069] in <6cd960837cc24c26bab2a0a29b597627>:0
[MonoDroid] at Java.Interop.JniPeerMembers+JniInstanceMethods.InvokeAbstractObjectMethod (System.String encodedMember, Java.Interop.IJavaPeerable self, Java.Interop.JniArgumentValue* parameters) [0x00014] in <6cd960837cc24c26bab2a0a29b597627>:0
[MonoDroid] at Android.Locations.Geocoder.GetFromLocationName (System.String locationName, System.Int32 maxResults) [0x0003c] in <d278c06ad5684d6882c743a94a93ebc2>:0
[MonoDroid] at Android.Locations.Geocoder+<>c__DisplayClass17_0.<GetFromLocationNameAsync>b__0 () [0x00000] in <d278c06ad5684d6882c743a94a93ebc2>:0
[MonoDroid] at System.Threading.Tasks.Task`1[TResult].InnerInvoke () [0x0000f] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Threading.Tasks.Task.Execute () [0x00010] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] --- End of stack trace from previous location where exception was thrown ---
[MonoDroid] at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x0003e] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at Xamarin.Forms.Maps.Android.GeocoderBackend+<GetPositionsForAddressAsync>d__1.MoveNext () [0x0006b] in <39c694c022be4f7b8a39897d372b2d00>:0
[MonoDroid] --- End of stack trace from previous location where exception was thrown ---
[MonoDroid] at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x0003e] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x00028] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x00008] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at Picaplant.Views.GeolocationPage+<HandleAdressCompleted>d__8.MoveNext () [0x00047] in /Users/OrcusZ/Documents/AutoEntrepreneur/Picaplant/Source/Picaplant/Views/GeolocationPage.xaml.cs:158
[MonoDroid] --- End of stack trace from previous location where exception was thrown ---
[MonoDroid] at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_0 (System.Object state) [0x00000] in <896ad1d315ca4ba7b117efb8dacaedcf>:0
[MonoDroid] at Android.App.SyncContext+<>c__DisplayClass2_0.<Post>b__0 () [0x00000] in <d278c06ad5684d6882c743a94a93ebc2>:0
[MonoDroid] at Java.Lang.Thread+RunnableImplementor.Run () [0x00008] in <d278c06ad5684d6882c743a94a93ebc2>:0
[MonoDroid] at Java.Lang.IRunnableInvoker.n_Run (System.IntPtr jnienv, System.IntPtr native__this) [0x00008] in <d278c06ad5684d6882c743a94a93ebc2>:0
[MonoDroid] at (wrapper dynamic-method) System.Object:6621ff63-14b8-4291-a222-45bff630bddc (intptr,intptr)
[MonoDroid] --- End of managed Java.IO.IOException stack trace ---
[MonoDroid] java.io.IOException: grpc failed
[MonoDroid] at android.location.Geocoder.getFromLocationName(Geocoder.java:178)
[MonoDroid]
EDIT 2 :
Same error with Xamarin Form Working with maps sample
Any idea ?

Answer 1

Here's a working cross-platform sample app. It runs in a KitKat 4.4 API Level 19 emulator and also in a Samsung Android device.
We also present a custom Geocoder implementation using HTTP requests given that the standard one works fine for an actual Android device but returns an empty response for the emulator.
XAML:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:Maps="clr-namespace:Xamarin.Forms.Maps;assembly=Xamarin.Forms.Maps.dll"
xmlns:local="clr-namespace:App20"
x:Class="App20.MainPage">
<ContentPage.Content>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="8*"></RowDefinition>
<RowDefinition Height="4*"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
<RowDefinition Height="*"></RowDefinition>
</Grid.RowDefinitions>
<Maps:Map x:Name="map1" Grid.Row="0"></Maps:Map>
<ListView ItemsSource="{Binding AddressList}" Grid.Row="1" />
<Button Text="Move To Region" Grid.Row="2" Clicked="Button_Clicked_Move"></Button>
<Button Text="Get Address" Grid.Row="3" Clicked="Button_Clicked_Address"></Button>
</Grid>
</ContentPage.Content>
</ContentPage>
CS:
public partial class MainPage : ContentPage
{
MyViewModel vm;
public MainPage()
{
InitializeComponent();
vm = new MyViewModel();
BindingContext = vm;
}
private void Button_Clicked_Move(object sender, EventArgs e)
{
map1.MoveToRegion(MapSpan.FromCenterAndRadius(
new Position(vm.Lat, vm.Lon), Distance.FromMiles(vm.Distance)));
}
private async void Button_Clicked_Address(object sender, EventArgs e)
{
Geocoder gc = new Geocoder();
var list = await gc.GetAddressesForPositionAsync(new Position(vm.Lat, vm.Lon));
if (list.Count() > 0)
{
foreach (string s in list)
vm.AddressList.Add(s);
}
else
{
MyGeocoder mgc = new MyGeocoder();
var mylist = await mgc.GetAddressesForPositionAsync(vm.Lat, vm.Lon, vm.Key);
foreach (string s in mylist)
vm.AddressList.Add(s);
}
}
}
View Model:
public class MyViewModel
{
public string Key { get; }
public double Lat { get; set; }
public double Lon { get; set; }
public double Distance { get; set; }
public ObservableCollection<string> AddressList { get; set; }
public MyViewModel()
{
Lat = 40.706501;
Lon = -74.011340;
Distance = 0.5;
Key = "YOUR_API_KEY";
AddressList = new ObservableCollection<string>();
}
}
Custom Geocoder:
public class MyGeocoder
{
public async Task<IEnumerable<string>> GetAddressesForPositionAsync(double lat, double lon, string key)
{
HttpClient client = new HttpClient();
var request = string.Format(#"https://maps.googleapis.com/maps/api/geocode/json?latlng={0},{1}&key={2}", lat, lon, key);
var json = await client.GetStringAsync(request);
var result = JObject.Parse(json)["results"];
List<string> list = new List<string>();
foreach (JToken jt in result)
list.Add((string)jt["formatted_address"]);
return list.AsEnumerable<string>();
}
}