DataReader问题 急！！！

Question

            while (dr.Read())
            {
                try
                {                    ClassesRowData crd = new ClassesRowData();
                    crd.ID1 = dr.GetInt32(dr.GetOrdinal("ID"));
                    crd.ParentID1 = dr.GetInt32(dr.GetOrdinal("ParentID"));
                    crd.Title = dr.GetString(dr.GetOrdinal("Title"));
                    crd.EnTitle1 = dr.GetString(dr.GetOrdinal("EnTitle")).ToString();
                    crd.IsOpen1 = dr.GetInt32(dr.GetOrdinal("IsOpen"));
                    crd.CanDelete1 = dr.GetInt32(dr.GetOrdinal("CanDelete"));
                    crd.OrderID1 = dr.GetInt32(dr.GetOrdinal("OrderID"));
                    crd.Url1 = dr.GetString(dr.GetOrdinal("Url"));
                    crd.ClassManager1 = dr.GetInt32(dr.GetOrdinal("ClassManager")).ToString();
                    list.Add(crd);
                }
                catch(Exception ex) 
                {
                    throw ex;
                }
            }   如上例子：
    在读取数据时如果数据库中某一条数据为空，应该怎样避免异常。

Answer 1

添加判断条件， dr.isDBNUll()

Answer 2

dr["id"]==DBNull.Value?"":dr["id"].ToString();

Answer 3

dr["id"]==DBNull.Value?"":dr["id"].ToString();恩，我一般也是这么处理的