百度（bd09）、高德（gcj02）、WGS84坐标系转标准平面坐标

百度、高德、WGS84为球面坐标系可以通过算法直接转换

通用参数：

        public static String BAIDU_LBS_TYPE = "bd09ll";
    
    　　 public static double pi = 3.1415926535897932384626;
        public static double a = 6378245.0D;
        public static double ee = 0.006693421622965943D;
        private static double X_PI= pi * 3000.0D / 180.0D;

 百度->高德->WGS84

/**
         * * 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 Gps bd09_To_Gcj02(double bd_lon, double bd_lat)
        {
            double x = bd_lon - 0.0065, y = bd_lat - 0.006;
            double z = Math.Sqrt(x * x + y * y) - 0.00002 * Math.Sin(y * pi);
            double theta = Math.Atan2(y, x) - 0.000003 * Math.Cos(x * pi);
            double gg_lon = z * Math.Cos(theta);
            double gg_lat = z * Math.Sin(theta);
            return new Gps() { lon = gg_lon, lat = gg_lat };
        }

        /**
        * * 火星坐标系 (GCJ-02) to 84 * * @param lon * @param lat * @return
        * */
        public static Gps gcj_To_Gps84(double lon, double lat)
        {
            Gps gps = transform(lon, lat);
            double lontitude = lon * 2 - gps.lon;
            double latitude = lat * 2 - gps.lat;
            return new Gps() { lat = latitude, lon = lontitude };
        }

        public static Gps transform(double lon, double lat)
        {
            if (outOfChina(lon, lat))
            {
                return new Gps() { lon = lon, lat = lat };
            }
            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 Gps() { lon = mgLon, lat = mgLat };
        }

        public static bool outOfChina(double lon, double lat)
        {
            if (lon < 72.004 || lon > 137.8347)
                return true;
            if (lat < 0.8293 || lat > 55.8271)
                return true;
            return false;
        }

        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;
        }

        /**
         * 84 to 火星坐标系 (GCJ-02)
         * 
         * @param lat
         * @param lon
         * @return
         */
        public static Gps gps84_To_Gcj02(double lon, double lat)
        {
            //if (outOfChina(lon, lat))
            //{
            //    return null;
            //}
            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 Gps() { lat=mgLat,lon=mgLon};
        }
        
                /**
         * 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 gg_lat
         * @param gg_lon
         */
        public static Gps gcj02_To_Bd09(double gg_lon, double gg_lat)
        {
            double x = gg_lon, y = gg_lat;
            double z = Math.Sqrt(x * x + y * y) + 0.00002 * Math.Sin(y * pi);
            double theta = Math.Atan2(y, x) + 0.000003 * Math.Cos(x * pi);
            double bd_lon = z * Math.Cos(theta) + 0.0065;
            double bd_lat = z * Math.Sin(theta) + 0.006;
            return new Gps() { lat=bd_lat,lon=bd_lon};
        }

标准的球面坐标要转到标准的平面坐标可以通过墨卡托投影实现

这里使用ARCGIS的API实现需要导入ESRI.ArcGIS.Geometry.dll、ESRI.ArcGIS.System.dll、ESRI.ArcGIS.Version.dll(dll下载)

        /// <summary>
        /// 平面转球面
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <returns></returns>
        public static Gps GetProject(double x, double y)
        {
            try
            {
                ESRI.ArcGIS.RuntimeManager.Bind(ESRI.ArcGIS.ProductCode.EngineOrDesktop);
                ISpatialReferenceFactory spatialReferenceFactory = new SpatialReferenceEnvironment();
                ISpatialReference pSpatialReference = spatialReferenceFactory.CreateProjectedCoordinateSystem(2437);//平面
                IGeographicCoordinateSystem projectedCoordinateSystem = spatialReferenceFactory.CreateGeographicCoordinateSystem(4326);//球面

                //进行坐标转换
                IPoint pt = new PointClass
                {
                    SpatialReference = pSpatialReference,
                    X = x,
                    Y = y
                };
                pt.Project(projectedCoordinateSystem);
                //System.Threading.Thread.Sleep(500);
                Gps xy = new Gps() { lat = pt.X, lon = pt.Y };
                return xy;
            }
            catch (Exception e)
            {
                var v = e.Message;
                return null;
            }



        }

代码中的2437和4326为坐标系的WKID，2437标识表示Beijing_1954_3_Degree_GK_CM_120E的坐标系，4326标识表示GCS_WGS_1984的坐标系（坐标系WKID对照信息）

球面转平面将 SpatialReference 赋的值与pt.Project()的参数互换

        /// <summary>
        /// 球面转平面
        /// </summary>
        /// <param name="x"></param>
        /// <param name="y"></param>
        /// <returns></returns>
        public static Gps GetProjectNew(double x, double y)
        {
            try
            {
                ESRI.ArcGIS.RuntimeManager.Bind(ESRI.ArcGIS.ProductCode.EngineOrDesktop);
                ISpatialReferenceFactory spatialReferenceFactory = new SpatialReferenceEnvironment();
                ISpatialReference pSpatialReference = spatialReferenceFactory.CreateProjectedCoordinateSystem(4549);//平面
                IGeographicCoordinateSystem projectedCoordinateSystem = spatialReferenceFactory.CreateGeographicCoordinateSystem(4326);//球面

                //进行坐标转换
                IPoint pt = new PointClass
                {
                    SpatialReference = projectedCoordinateSystem,
                    X = x,
                    Y = y
                };
                pt.Project(pSpatialReference);
                //System.Threading.Thread.Sleep(500);
                Gps xy = new Gps() { lat = pt.X, lon = pt.Y };
                return xy;
            }
            catch (Exception e)
            {
                var v = e.Message;
                return null;
            }



        }

在使用.net core编写demo时有遇到ESRI.ArcGIS.Version.dll无法读取加载情况，要修改配置信息：右键项目->属性->生成->目标平台->x86