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);
}
}