private void OnLocationChanged( GeoPosition location )
{
var evt = LocationChanged;
if ( evt != null )
{
evt( this, new LocationChangedEventArgs( location ) );
}
}
/// <summary>
/// Computes the distance to another GeoPosition.
/// </summary>
public double DistanceTo( GeoPosition other )
{
double lat1 = this.Latitude * RadianCoeff,
lat2 = other.Latitude * RadianCoeff,
lon1 = this.Longitude * RadianCoeff,
lon2 = other.Longitude * RadianCoeff;
return EarthRadiusInKilometers * 2 * Math.Asin( Math.Min( 1, Math.Sqrt( ( Math.Pow( Math.Sin( ( lat2 - lat1 ) / 2.0 ), 2.0 ) + Math.Cos( lat1 ) * Math.Cos( lat2 ) * Math.Pow( Math.Sin( ( lon2 - lon1 ) / 2.0 ), 2.0 ) ) ) ) );
}
/// <summary>
/// Asynchronously gets the user's location.
/// </summary>
public async Task<Tuple<GeoPosition, GeoLocationStatus>> GetLocationAsync()
{
try
{
var geoPosition = await _locator.GetGeopositionAsync();
_lastKnownLocation = PositionFromCoordinate( geoPosition.Coordinate );
return Tuple.Create( _lastKnownLocation, GeoLocationStatus.Success );
}
catch
{
return Tuple.Create( (GeoPosition) null, GeoLocationStatus.Error );
}
}
/// <summary>
/// Creates a new LocationChangedEventArgs.
/// </summary>
public LocationChangedEventArgs(GeoPosition location)
{
Location = location;
}
/// <summary>
/// Creates a new LocationChangedEventArgs.
/// </summary>
public LocationChangedEventArgs( GeoPosition location )
{
Location = location;
}
/// <summary>
/// Occurs when the user's position changes.
/// </summary>
private void Locator_PositionChanged( Geolocator sender, PositionChangedEventArgs args )
{
_lastKnownLocation = PositionFromCoordinate( args.Position.Coordinate );
OnLocationChanged( _lastKnownLocation );
}