偏移数据库c#

private void TransGPSFromL(String latStr, String logStr)
    {
        try
        {

            //////////////gps转换
            double lat = double.Parse(latStr);
            double log = double.Parse(logStr);
            int nLat = (int)(lat * 10);
            int nLog = (int)(log * 10);

            string sql = "select offLat,offLog from gpst where lat = @nLat and log=@nLog;";
            MySqlParameter[] paras = new MySqlParameter[2];
            paras[0] = new MySqlParameter("@nLat", nLat);
            paras[1] = new MySqlParameter("@nLog", nLog);
            using (MySqlDataReader dr = MySqlHelper.ExecuteReader(mysqlYunfeng, sql, paras))
            {

                if (dr.HasRows == true && dr.Read())
                {

                    double offLat = int.Parse(dr[0].ToString());
                    double offLog = int.Parse(dr[1].ToString());

                    offLat = offLat * 0.0001;
                    offLog = offLog * 0.0001;

                    lat = lat + offLat;
                    log = log + offLog;

                    //输出json
                    GPSNode node = new GPSNode();
                    node.OffLat = lat;
                    node.OffLog = log;

                    //JavaScriptSerializer类在System.Web.Extensions.dll中，注意添加这个引用
                    JavaScriptSerializer serializer = new JavaScriptSerializer();
                    //JSON序列化
                    string result = serializer.Serialize(node);
                    Response.Write(result);

                }
                else
                {
                    Response.Write("Error:-1");
                }

            }

        }
        catch (Exception exce)
        {
            Response.Write("Error:" + exce.Message);
        }
    }