windows phone 7 定位（获取经纬度）,然后找到经纬度所在的位置(城市信息)

前几天做项目用到, 代码贴给大家。

/// <summary>
        /// 获取当前位置的经纬度
        /// </summary>
        /// <returns></returns>

   public static double[] GetLocationProperty() 
        {
            double[] latLong = new double[2];

            GeoCoordinateWatcher watcher = new GeoCoordinateWatcher();
            watcher.TryStart(false,TimeSpan.FromMilliseconds(1000));
            GeoCoordinate coord = watcher.Position.Location;

            if (coord.IsUnknown != true)
            {
                latLong[0] = coord.Latitude;
                latLong[1] = coord.Longitude;
            }
            return latLong;


        }



 #region 两个经纬度之差求的距离
        private const double EARTH_RADIUS = 6378.137;
        private static double rad(double d)
        {
            return d * Math.PI / 180.0;
        }

        public static double GetDistance(double lat1, double lng1, double lat2, double lng2)
        {
            double radLat1 = rad(lat1);
            double radLat2 = rad(lat2);
            double a = radLat1 - radLat2;
            double b = rad(lng1) - rad(lng2);
            double s = 2 * Math.Asin(Math.Sqrt(Math.Pow(Math.Sin(a / 2), 2) +
             Math.Cos(radLat1) * Math.Cos(radLat2) * Math.Pow(Math.Sin(b / 2), 2)));
            s = s * EARTH_RADIUS;
            s = Math.Round(s * 10000) / 10000;
            return s;
        }
        #endregion

//URL接口来自诺基亚地图
public static Uri Get_CityNameOnMap(double slatitude, double slongitude) 
        {
            string urlString = "http://loc.desktop.maps.svc.ovi.com/geocoder/rgc/1.0?" + "lat=" + slatitude + "&long=" + slongitude + "&output=json";
            return new Uri(urlString, UriKind.RelativeOrAbsolute);
        }