GeoCoordinate.GetDistanceTo()
is found in System.Device.Location
namespace. But windows 8.1 (Runtime apps) apps use Windows.Devices.Geolocation
namespace where GetDistanceTo()
method is not present.
So you can calculate the distance yourself by using the Haversine formula. Here is the wikipedia Haversine page, you can know about the formula from there.
You can use the below C# code which uses Haversine formula to calculate the distance between two coordinates.
using System;
namespace HaversineFormula
{
/// <summary>
/// The distance type to return the results in.
/// </summary>
public enum DistanceType { Miles, Kilometers };
/// <summary>
/// Specifies a Latitude / Longitude point.
/// </summary>
public struct Position
{
public double Latitude;
public double Longitude;
}
class Haversine
{
/// <summary>
/// Returns the distance in miles or kilometers of any two
/// latitude / longitude points.
/// </summary>
public double Distance(Position pos1, Position pos2, DistanceType type)
{
double R = (type == DistanceType.Miles) ? 3960 : 6371;
double dLat = this.toRadian(pos2.Latitude - pos1.Latitude);
double dLon = this.toRadian(pos2.Longitude - pos1.Longitude);
double a = Math.Sin(dLat / 2) * Math.Sin(dLat / 2) +
Math.Cos(this.toRadian(pos1.Latitude)) * Math.Cos(this.toRadian(pos2.Latitude)) *
Math.Sin(dLon / 2) * Math.Sin(dLon / 2);
double c = 2 * Math.Asin(Math.Min(1, Math.Sqrt(a)));
double d = R * c;
return d;
}
/// <summary>
/// Convert to Radians.
/// </summary>
private double toRadian(double val)
{
return (Math.PI / 180) * val;
}
}