How to wait for QureryCompleted event?

How to wait for QureryCompleted event?

I created a small application to get the Longitude and Latitude and to
convert it to actual address:
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Device.Location;
using System.Linq;
using System.Net;
using System.Threading;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Navigation;
using Microsoft.Phone.Controls;
using Microsoft.Phone.Maps.Services;
using Microsoft.Phone.Shell;
using PhoneApp1.Resources;
using SunAngle;
using Windows.Devices.Geolocation;
namespace PhoneApp1
{
public partial class MainPage : PhoneApplicationPage
{
private GeoCoordinate Location;
public ObservableCollection<string> Addresses { get; set; }
// Constructor
public MainPage()
{
InitializeComponent();
// Sample code to localize the ApplicationBar
//BuildLocalizedApplicationBar();
}
protected override async void OnNavigatedTo( NavigationEventArgs e )
{
await GetLocation();
}
public async Task GetLocation()
{
Location = await CoordinateConverter.GetLocation();
ReverseGeoCoding.StartReverseGeoCoding( Location );
//ReverseGeoCoding.done.WaitOne();
string Address = ReverseGeoCoding.Address;
}
}
public static class ReverseGeoCoding
{
public static ObservableCollection<string> Addresses = new
ObservableCollection< string >();
public static string Address;
public static bool Completed;
public static AutoResetEvent done = new AutoResetEvent( true );
public static void StartReverseGeoCoding( GeoCoordinate Location )
{
Completed = false;
var reverseGeocode = new ReverseGeocodeQuery();
reverseGeocode.GeoCoordinate = new GeoCoordinate(
Location.Latitude, Location.Longitude );
reverseGeocode.QueryCompleted += ReverseGeocodeQueryCompleted;
done.Reset();
reverseGeocode.QueryAsync();
}
public static void ReverseGeocodeQueryCompleted( object sender,
QueryCompletedEventArgs<System.Collections.Generic.IList<MapLocation>>
e )
{
var reverseGeocode = sender as ReverseGeocodeQuery;
if ( reverseGeocode != null )
{
reverseGeocode.QueryCompleted -= ReverseGeocodeQueryCompleted;
}
//Microsoft.Phone.Maps.Services.MapAddress address;
Addresses.Clear();
if ( !e.Cancelled )
{
foreach ( var address in e.Result.Select( adrInfo =>
adrInfo.Information.Address ) )
{
Addresses.Add( string.Format( "{0} {1}, {2} {3} {4}, {5}",
address.HouseNumber,
address.Street,
address.City,
address.State,
address.PostalCode,
address.Country ).Trim() );
}
}
if ( Addresses.Count > 0 )
{
Address = Addresses[ 0 ].ToString();
}
else
{
Address = "";
}
done.Set();
Completed = true;
}
}
public static class CoordinateConverter
{
public static GeoCoordinate ConvertGeocoordinate( Geocoordinate
geocoordinate )
{
return new GeoCoordinate
(
geocoordinate.Latitude,
geocoordinate.Longitude,
geocoordinate.Altitude ?? Double.NaN,
geocoordinate.Accuracy,
geocoordinate.AltitudeAccuracy ?? Double.NaN,
geocoordinate.Speed ?? Double.NaN,
geocoordinate.Heading ?? Double.NaN
);
}
public static async Task<GeoCoordinate> GetLocation()
{
// Get current location.
Geolocator myGeolocator = new Geolocator();
myGeolocator.DesiredAccuracy = PositionAccuracy.High;
//myGeolocator.DesiredAccuracyInMeters = 50;
Geocoordinate myGeocoordinate = null;
try
{
Geoposition myGeoposition = await
myGeolocator.GetGeopositionAsync
(
maximumAge: TimeSpan.FromMinutes( 1 ),
timeout: TimeSpan.FromSeconds( 10 )
);
myGeocoordinate = myGeoposition.Coordinate;
}
catch ( Exception ex )
{
if ( (uint)ex.HResult == 0x80004004 )
{
// the application does not have the right capability or
the location master switch is off
MessageBox.Show( "location is disabled in phone settings" );
}
}
if ( myGeocoordinate == null )
{
return GeoCoordinate.Unknown;
}
GeoCoordinate myGeoCoordinate =
CoordinateConverter.ConvertGeocoordinate( myGeocoordinate );
return myGeoCoordinate;
}
}
}
The code works fine, i.e. the ReverseGeocodeQueryCompleted is called and
the address is being calculated properly. However,
ReverseGeocodeQueryCompleted occurs after GetLocation() is completed and
the address assigned to Address is null.
My question is how to make
ReverseGeoCoding.StartReverseGeoCoding( Location );
wait for the completion of the of:
ReverseGeocodeQueryCompleted( object sender,
QueryCompletedEventArgs<System.Collections.Generic.IList<MapLocation>> e )
{
....
}
I tried with AutoResetEvent and WaitOne, but the whole thread is stops and
the code never gets to ReverseGeocodeQueryCompleted().
I am open to suggestions how to solve this problem.
EitanB