znyc.gps_service/GPSBusiness/Util/GpsUtil.cs

using System;

namespace GPSBuSiness.Util
{

    public static class GPSUtil
    {

        public static double pi = 3.1415926535897932384626;
        public static double x_pi = 3.14159265358979324 * 3000.0 / 180.0;
        public static double a = 6378245.0;
        public static double ee = 0.00669342162296594323;
        private static double EARTH_RADIUS = 6378.137;
        private static double rad(double d)
        {
            return d * Math.PI / 180.0;
        }
        public static double transformLat(double x, double y)
        {
            double ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y
                    + 0.2 * Math.Sqrt(Math.Abs(x));
            ret += (20.0 * Math.Sin(6.0 * x * pi) + 20.0 * Math.Sin(2.0 * x * pi)) * 2.0 / 3.0;
            ret += (20.0 * Math.Sin(y * pi) + 40.0 * Math.Sin(y / 3.0 * pi)) * 2.0 / 3.0;
            ret += (160.0 * Math.Sin(y / 12.0 * pi) + 320 * Math.Sin(y * pi / 30.0)) * 2.0 / 3.0;
            return ret;
        }

        public static double transformLon(double x, double y)
        {
            double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1
                    * Math.Sqrt(Math.Abs(x));
            ret += (20.0 * Math.Sin(6.0 * x * pi) + 20.0 * Math.Sin(2.0 * x * pi)) * 2.0 / 3.0;
            ret += (20.0 * Math.Sin(x * pi) + 40.0 * Math.Sin(x / 3.0 * pi)) * 2.0 / 3.0;
            ret += (150.0 * Math.Sin(x / 12.0 * pi) + 300.0 * Math.Sin(x / 30.0
                    * pi)) * 2.0 / 3.0;
            return ret;
        }

        public static Boolean outOfChina(double lat, double lon)
        {
            if (lon < 72.004 || lon > 137.8347)
                return true;
            if (lat < 0.8293 || lat > 55.8271)
                return true;
            return false;
        }
        /**
         * 84 to 火星坐标系 (GCJ-02) World Geodetic System ==> Mars Geodetic System
         *
         * @param lat
         * @param lon
         * @return
         */
        public static double[] gps84_To_Gcj02(double lat, double lon)
        {
            if (outOfChina(lat, lon))
            {
                return new double[] { lat, lon };
            }
            double dLat = transformLat(lon - 105.0, lat - 35.0);
            double dLon = transformLon(lon - 105.0, lat - 35.0);
            double radLat = lat / 180.0 * pi;
            double magic = Math.Sin(radLat);
            magic = 1 - ee * magic * magic;
            double SqrtMagic = Math.Sqrt(magic);
            dLat = (dLat * 180.0) / ((a * (1 - ee)) / (magic * SqrtMagic) * pi);
            dLon = (dLon * 180.0) / (a / SqrtMagic * Math.Cos(radLat) * pi);
            double mgLat = lat + dLat;
            double mgLon = lon + dLon;
            return new double[] { mgLat, mgLon };
        }

        /**
         * * 火星坐标系 (GCJ-02) to 84 * * @param lon * @param lat * @return
         * */
        public static double[] gcj02_To_Gps84(double lat, double lon)
        {
            double[] gps = gps84_To_Gcj02(lat, lon);
            double lontitude = lon * 2 - gps[1];
            double latitude = lat * 2 - gps[0];
            return new double[] { latitude, lontitude };
        }
        /**
         * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法 将 GCJ-02 坐标转换成 BD-09 坐标
         *
         * @param lat
         * @param lon
         */
        public static double[] gcj02_To_Bd09(double lat, double lon)
        {
            double x = lon, y = lat;
            double z = Math.Sqrt(x * x + y * y) + 0.00002 * Math.Sin(y * x_pi);
            double theta = Math.Atan2(y, x) + 0.000003 * Math.Cos(x * x_pi);
            double tempLon = z * Math.Cos(theta) + 0.0065;
            double tempLat = z * Math.Sin(theta) + 0.006;
            double[] gps = { tempLat, tempLon };
            return gps;
        }

        /**
         * * 火星坐标系 (GCJ-02) 与百度坐标系 (BD-09) 的转换算法 * * 将 BD-09 坐标转换成GCJ-02 坐标 * * @param
         * bd_lat * @param bd_lon * @return
         */
        public static double[] bd09_To_Gcj02(double lat, double lon)
        {
            double x = lon - 0.0065, y = lat - 0.006;
            double z = Math.Sqrt(x * x + y * y) - 0.00002 * Math.Sin(y * x_pi);
            double theta = Math.Atan2(y, x) - 0.000003 * Math.Cos(x * x_pi);
            double tempLon = z * Math.Cos(theta);
            double tempLat = z * Math.Sin(theta);
            double[] gps = { tempLat, tempLon };
            return gps;
        }

        /**将gps84转为bd09
         * @param lat
         * @param lon
         * @return
         */
        public static double[] gps84_To_bd09(double lat, double lon)
        {
            double[] gcj02 = gps84_To_Gcj02(lat, lon);
            double[] bd09 = gcj02_To_Bd09(gcj02[0], gcj02[1]);
            return bd09;
        }
        public static double[] bd09_To_gps84(double lat, double lon)
        {
            double[] gcj02 = bd09_To_Gcj02(lat, lon);
            double[] gps84 = gcj02_To_Gps84(gcj02[0], gcj02[1]);
            //保留小数点后六位
            gps84[0] = retain6(gps84[0]);
            gps84[1] = retain6(gps84[1]);
            return gps84;
        }

        /**保留小数点后六位
         * @param num
         * @return
         */
        private static double retain6(double num)
        {
            String result = String.Format("%.6f", num);
            return double.Parse(result);
        }



        /**
         * 计算两个经纬度之间的距离
         * @param lat1
         * @param lng1
         * @param lat2
         * @param lng2
         * @return
         */
        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 * 1000);
            return s;
        }

                /**
         *算角度
         * @param lat_a 纬度1
         * @param lng_a 经度1
         * @param lat_b 纬度2
         * @param lng_b 经度2
         * @return
         */
        public static double GetAngle(double lng_a, double lat_a, double lng_b, double lat_b)
        {

            double y = Math.Sin(lng_b - lng_a) * Math.Cos(lat_b);
            double x = Math.Cos(lat_a) * Math.Sin(lat_b) - Math.Sin(lat_a) * Math.Cos(lat_b) * Math.Cos(lng_b - lng_a);
            double brng = Math.Atan2(y, x);
            if (brng < 0)
                brng = brng + 360;
            return brng;

        }
    }

}