关键代码：

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using YanZhiwei.DotNet2.Utilities.Models;
namespace YanZhiwei.DotNet2.Utilities.Common
{
    /// <summary>
    /// 地图纠偏数据帮助类
    /// </summary>
    public class MapOffsetDataHelper
    {
        #region 构造函数以及变量
        PRivate string offsetFullPath = string.Empty;
        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="path">纠偏数据文件路径</param>
        public MapOffsetDataHelper(string path)
        {
            offsetFullPath = path;
        }
        #endregion
        #region 私有方法
        private void GetOffsetData(Action<MapCoord> mapCoordHanlder)
        {
            using (FileStream stream = new FileStream(offsetFullPath, FileMode.OpenOrCreate, Fileaccess.Read))
            {
                using (BinaryReader reader = new BinaryReader(stream))
                {
                    int _size = (int)stream.Length / 8;
                    for (int i = 0; i < _size; i++)
                    {
                        byte[] _source = reader.ReadBytes(8);
                        MapCoord _coord = ToCoord(_source);
                        mapCoordHanlder(_coord);
                    }
                }
            }
        }
        /// <summary>
        /// 将字节转化为具体的数据对象
        /// </summary>
        /// <param name="bytes">bytes</param>
        /// <returns>MapCoord</returns>
        private MapCoord ToCoord(byte[] bytes)
        {
            //经度,纬度,x偏移量,y偏移量 【均两个字节】
            MapCoord _coord = new MapCoord();
            byte[] _b1 = new byte[2], _b2 = new byte[2], _b3 = new byte[2], _b4 = new byte[2];
            Array.Copy(bytes, 0, _b1, 0, 2);
            Array.Copy(bytes, 2, _b2, 0, 2);
            Array.Copy(bytes, 4, _b3, 0, 2);
            Array.Copy(bytes, 6, _b4, 0, 2);
            _coord.Lon = BitConverter.ToInt16(_b1, 0);
            _coord.Lat = BitConverter.ToInt16(_b2, 0);
            _coord.X_off = BitConverter.ToInt16(_b3, 0);
            _coord.Y_off = BitConverter.ToInt16(_b4, 0);
            return _coord;
        }
        #endregion 
        #region 获取纠偏数据集合
        /// <summary>
        /// 获取纠偏数据集合
        /// </summary>
        /// <returns>纠偏数据集合</returns>
        public List<MapCoord> GetMapCoordList()
        {
            List<MapCoord> _mapCoordList = new List<MapCoord>();
            GetOffsetData(c => _mapCoordList.Add(c));
            return _mapCoordList;
        }
        /// <summary>
        /// 获取纠偏数据集合
        /// </summary>
        /// <returns>纠偏数据集合</returns>
        public ArrayList GetMapCoordArrayList()
        {
            ArrayList _mapCoordArrayList = new ArrayList();
            GetOffsetData(c => _mapCoordArrayList.Add(c));
            return _mapCoordArrayList;
        }
        #endregion
    }
}

-----------------------------------------------------------------------------------------------

using System.Collections;
using YanZhiwei.DotNet2.Utilities.Models;
using YanZhiwei.DotNet2.Utilities.Tool;
namespace YanZhiwei.DotNet2.Utilities.Common
{
    /// <summary>
    /// 地图纠偏 帮助类
    /// </summary>
    public class MapOffsetHelper
    {
        /*
         *参考：
         *1.http://www.apkbus.com/forum.php?mod=viewthread&tid=137621&extra=page%3D1&page=1
         *2.http://yanue.net/post-122.html
         *3.http://go2log.com/2011/08/30/%E4%B8%AD%E5%9B%BD%E5%9C%B0%E5%9B%BE%E5%81%8F%E7%A7%BB%E6%A0%A1%E6%AD%A3php%E7%AE%97%E6%B3%95/
         *4.http://www.devdiv.com/ios_gps_google_-blog-60266-10835.html
         */
        #region 构造函数以及变量
        private ArrayList mapCoordArrayList;
        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="offsetData">纠偏数据</param>
        public MapOffsetHelper(ArrayList offsetData)
        {
            mapCoordArrayList = offsetData;
        }
        #endregion
        #region 私有方法
        private MapCoord QueryOffSetData(LatLngPoint point)
        {
            MapCoord _search = new MapCoord();
            _search.Lat = (int)(point.LatY * 100);
            _search.Lon = (int)(point.LonX * 100);
            MapOffsetComparer rc = new MapOffsetComparer();
            int _findedIndex = mapCoordArrayList.BinarySearch(0, mapCoordArrayList.Count, _search, rc);
            MapCoord _findedCoord = (MapCoord)mapCoordArrayList[_findedIndex];
            return _findedCoord;
        }
        #endregion 
        #region 地球坐标(WGS-84)转火星坐标 (GCJ-02)
        /// <summary>
        /// 地球坐标(WGS-84)转火星坐标 (GCJ-02)
        /// </summary>
        /// <param name="wgsPoint">地球坐标(WGS-84)</param>
        /// <returns>火星坐标 (GCJ-02)</returns>
        public LatLngPoint WGS84ToGCJ02(LatLngPoint wgsPoint)
        {
            MapCoord _findedCoord = QueryOffSetData(wgsPoint);
            double _pixY = MapHelper.LatToPixel(wgsPoint.LatY, 18);
            double _pixX = MapHelper.LonToPixel(wgsPoint.LonX, 18);
            _pixY += _findedCoord.Y_off;
            _pixX += _findedCoord.X_off;
            double _lat = MapHelper.PixelToLat(_pixY, 18);
            double _lng = MapHelper.PixelToLon(_pixX, 18);
            return new LatLngPoint(_lat, _lng);
        }
        #endregion
        #region 火星坐标转 (GCJ-02)地球坐标(WGS-84)
        /// <summary>
        /// 火星坐标转 (GCJ-02)地球坐标(WGS-84)
        /// </summary>
        /// <param name="gcjPoint">火星坐标转 (GCJ-02)</param>
        /// <returns>地球坐标(WGS-84)</returns>
        public LatLngPoint GCJ02ToWGS84(LatLngPoint gcjPoint)
        {
            MapCoord _findedCoord = QueryOffSetData(gcjPoint);
            double _pixY = MapHelper.LatToPixel(gcjPoint.LatY, 18);
            double _pixX = MapHelper.LonToPixel(gcjPoint.LonX, 18);
            _pixY -= _findedCoord.Y_off;
            _pixX -= _findedCoord.X_off;
            double _lat = MapHelper.PixelToLat(_pixY, 18);
            double _lng = MapHelper.PixelToLon(_pixX, 18);
            return new LatLngPoint(_lat, _lng);
        }
        #endregion
    }
}