private DataTable CovertDataType(DataTable orgDataTable, string colNames, string convertCol, YstPack.Common.ColumnType convertDataType)
        {
            DataTable dt = new DataTable();
            //克隆表结构
            dt = orgDataTable.Clone();
            foreach (DataColumn column in dt.Columns)
            {
                if (column.ColumnName == convertCol)
                {
                    //修改列类型
                    column.DataType = typeof(Guid);
                }
            }

            string[] colArry = colNames.Split(',');

            foreach (DataRow dr in orgDataTable.Rows)
            {
                DataRow newdr = dt.NewRow();
                foreach (string str in colArry)
                {
                    if (str == convertCol)//转换列数据类型
                    {
                        switch (convertDataType)
                        {
                            case YstPack.Common.ColumnType.唯一标识:
                                newdr[str] = new Guid(dr[str].ToString());
                                break;
                            default:
                                break;
                        }
                    }
                    else
                    {

                        newdr[str] = dr[str];//不需要转化，直接赋值，但是这里就抛出异常！
                    }
                }
                dt.Rows.Add(newdr);
            }
            return dt;
        }