C# 处理 google map 经纬度偏移量

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
namespace WSGPSGateway.BLL
{
    public class LocationLogic
    {
        public LocationLogic() { }
        private static volatile LocationLogic _LocationLogic = new LocationLogic();
        /// <summary>
        /// 得到实例
        /// </summary>
        /// <returns></returns>
        public static LocationLogic GetInstance()
        {
            if (_LocationLogic == null)
            {
                lock (typeof(LocationLogic))
                {
                    if (_LocationLogic == null)
                    {
                        _LocationLogic = new LocationLogic();
                    }
                }
            }
            return _LocationLogic;
        }
       /// <summary>
       /// 得到经度和纬度
       /// </summary>
       /// <param name="lat"></param>
       /// <param name="lng"></param>
       /// <returns></returns>
        public decimal[] GetLatLng(decimal lat, decimal lng)
        {
            int PX, PY;
            decimal? PX1, PY1;
            decimal? OX;
            decimal? OY;
            decimal[] LatLng = new decimal[] { lat, lng };
            //传入两个参数 ，经度和纬度 ，然后返回经过解析的经度和纬度
            try
            {
                DAL.DeviceinfoDataSetTableAdapters.deviceinfoAdapter da = new DAL.DeviceinfoDataSetTableAdapters.deviceinfoAdapter();
                da.P_GETLATLNG(lat, lng, out OX, out OY);
                OX = Convert.ToDecimal(OX);
                OY = Convert.ToDecimal(OY);
                if (OX != 0 && OY != 0)
                {
                    Map.LatLongToPixelXY(Convert.ToDouble(lat), Convert.ToDouble(lng), 18, out PX, out PY);
                    PX1 = PX + OX;
                    PY1 = PY + OY;
                    LatLng[0] = Convert.ToDecimal(Map.PixelYToLat(Convert.ToDouble(PY1), 18));
                    LatLng[1] = Convert.ToDecimal(Map.PixelXToLng(Convert.ToDouble(PX1), 18));
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
            return LatLng;
        }
    }
}