geolocalisation is very slow - c#-4.0

Question

I've a application for the geolocalisation and I retrieve the current geoposition but the display on the application is VERY slow...
The constructor :
public TaskGeo()
{
InitializeComponent();
_geolocator = new Geolocator();
_geolocator.DesiredAccuracy = PositionAccuracy.High;
_geolocator.MovementThreshold = 100;
_geolocator.PositionChanged += _geolocator_PositionChanged;
_geolocator.StatusChanged += _geolocator_StatusChanged;
if (_geolocator.LocationStatus == PositionStatus.Disabled)
this.DisplayNeedGPS();
}
the code for the display on the app :
void _geolocator_PositionChanged(Geolocator sender, PositionChangedEventArgs args)
{
// saving and display of the position
App.RootFrame.Dispatcher.BeginInvoke(() =>
{
this._CurrentPosition = args.Position;
this.lblLon.Text = "Lon: " + this._CurrentPosition.Coordinate.Longitude;
this.lblLat.Text = "Lat: " + this._CurrentPosition.Coordinate.Latitude;
this.LocationChanged(this._CurrentPosition.Coordinate.Longitude, this._CurrentPosition.Coordinate.Latitude);
});
}
And the code for the query :
private void LocationChanged(double lat, double lon)
{
ReverseGeocodeQuery rgq = new ReverseGeocodeQuery();
rgq.GeoCoordinate = new GeoCoordinate(lat, lon);
rgq.QueryCompleted += rgq_QueryCompleted;
rgq.QueryAsync();
}
How can I improve the code to display faster the position ? Thanks in advance !

Answer 1

Getting this sort of information is basically pretty slow. To quote the great Louis C. K. "It is going to space, give it a second". Because you've specified PositionAccuracy.High this means that the location must be found using GPS, which is comparatively slow, and not any of the faster fallback methods such as using local wi-fi or cell phone towers.
You could reduce your demands for accuracy overall or initially request a lower accuracy and then refine it once the information from the GPS is available. The second option is better. If you look at a map application they typically do this by showing you about where you are and then improving it after the GPS lock is acquired.