如何获取数据表的最后 5 行？

Question

How do I get the last 5 rows of a datatable? I tried something like this:

var Long_bottom = LongSlection.Last(5);

Where LongSlection is a DataRow. But I had an error, any idea?

Answer 1

Not sure what you have got here

var Long_bottom = LongSlection.Last(5);

Assuming you have a DataTable and you want to get the last 5 rows you can do that via

datatable1.AsEnumerable().Reverse().Take(5);

Take and Skip return the specific number of elments (parameter is int) while which is not the case with Last you get the last element or you need a predicate for checking conditions or checks within the row.

Answer 2

This SHOULD do it. but it's untested!

IEnumerable<DataRow> lastRows = table.AsEnumerable().Skip(table.Rows.Count - 2).ToList();

Or:

table.AsEnumerable().Reverse().Take(2);

Edit: Modified to get the last TWO, as per the OPs request.

Answer 3

How about

Datarow[] dr = dt.Rows.Cast<DataRow>().Skip(dt.Rows.Count - 5).ToArray();

OR

dt.Rows.Cast<DataRow>().Reverse().Take(5);

Here 5 is the last number of rows to take.

Answer 4

我需要CopyToDataTable()来完成任务：

dt = dt.AsEnumerable().Reverse().Take(5).CopyToDataTable();