遍历DataTable中列头以d开头的列，都格式化2为小数~~
有更好的处理方式吗？

 var listColumns = new List<string>();
            foreach (DataTable item in SysVar.FCurryFormInfo.dsBillDataSet.Tables)
            {
                listColumns.Clear();
                for (int i = 0; i < item.Columns.Count; i++)
                {
                    //只处理d开头数值，i开头整形不用处理
                    if (item.Columns[i].ColumnName.Left(1).ToLower().Equals("d"))
                    {
                        listColumns.Add(item.Columns[i].ColumnName);
                    }
                }
                foreach (DataRow dataRow in item.Rows)
                {
                    foreach (string str in listColumns)
                    {
                        dataRow.BeginEdit(); 
                        dataRow[str] = Math.Round(dataRow[str].ToStringExt().ToDecimalExt(0), 2, MidpointRounding.AwayFromZero);
                        dataRow.EndEdit();
                    }
                }
            }