.net - 使用字段子字符串通过 Linq to DataSet 对 DataTable 进行排序

Question

我想使用两个排序值通过 Linq to DataSet 来订购 DataTable。然而，这两个值来自拆分和解析同一字段(不要问我为什么!)。

我尝试这样做:

var query = from row in dtReports.AsEnumerable()
            orderby row.Field<string>("ReportNumber").Substring(0,4),
                int.Parse(row.Field<string>("ReportNumber").Substring(5))
            select row

DataTable dt = query.AsDataView().ToTable()

但是我得到“使用投影后无法创建 DataView”。

然后我也尝试过:

var query = from element in (
                from row in dtReports.AsEnumerable()
                let year = row.Field<string>("ReportNumber").Substring(0, 4)
                let num = int.Parse(row.Field<string>("ReportNumber").Substring(5))
                select row, year, num)
            orderby element.year, element.num
            select element.row

DataTable dt = query.AsDataView().ToTable()

我一直收到同样的错误。

这是怎么做到的？

---

我要感谢大家的回答。最终的解决方案非常简单:

var query = from row in dtReports.AsEnumerable()
            let year = row.Field<string>("ReportNumber").Substring(0, 4)
            let num = int.Parse(row.Field<string>("ReportNumber").Substring(5))
            orderby year, num
            select row

DataTable dt = query.CopyToDataTable()

Answer 1

var query = dtReports.AsEnumerable()
              .OrderBy(x => x.Field<string>("ReportNumber").Substring(0, 4))
              .ThenBy(x => x.Field<string>("ReportNumber").Substring(5));
var dt = query.CopyToDataTable<DataRow>();