Dealer dl = new Dealer();
        using (SqlDataReader dr = SqlHelper.ExecuteReader(CommandType.StoredProcedure, "searchOnDealer", new SqlParameter("@ID", dID)))
        {
            if (dr.HasRows)
            {
                dl.ID = dr.GetInt32(0);
                dl.Name = dr.GetString(1);
                dl.Address = dr.GetString(2);
                dl.Theme = dr.GetInt32(5);
            }
           
        }

while(reader.Read())
{
    dl.ID = reader.GetInt32(0);
    dl.Name = reader.GetString(1);
    dl.Address = reader.GetString(2);
    dl.Theme = reader.GetInt32(5);

}

------解决方案--------------------
if (dr.HasRows && dr.Read())  
           {
               int id=0;
  int.TryPase(dr["字段名1"].ToString();,out id);
dl.ID=id;
               dl.Name = dr["字段名2"].ToString();
               dl.Address = dr["字段名3"].ToString();
               
               int theme=0;
  int.TryPase(dr["字段名5"].ToString();,out theme);
dl.Theme =theme; //如果确定数据没有问题,就用Parse()
           }