LINQ具有多项选择和按多项选择分组

Question

i have a table like this:

First Field | Second Field |  Third Field   |   Fourth Field
------------+--------------+----------------+----------------
 5      |     aaaa     |      47            |       abc
 5      |     aaaa     |      57            |       def
 5      |     aaaa     |      63            |       xyz
 5      |     bbbb     |      39            |       www
 5      |     bbbb     |      37            |       lol
 5      |     cccc     |      84            |       yuy

I want to group this table by first and the second field, but i want to get only the rows with the biggest third fields.

How can i do this via LINQ in c#?

var curi = (from row in customClassList.AsEnumerable()
                    group row by new
                    {
                        First = row.FirstField.ToString(),
                        Second = row.SecondSield.ToString(),
                    } into grp
                    select new FieldsClass
                    {
                        First = grp.Key.First,
                        Second = grp.Key.Second,
                        Third = grp.Select(p => p.ThirdField).Max().ToShort(),
                        Fourth = grp.Key.Fourth
                    }).ToList();

This is my expected result:

First Field | Second Field |  Third Field   |   Fourth Field
------------+--------------+----------------+----------------
 5      |     aaaa     |      63            |       xyz
 5      |     bbbb     |      39            |       www
 5      |     cccc     |      84            |       yuy

Answer 1

How about

var result = customClassList.GroupBy(x => new {x.FirstField, x.SecondField})
                            .Select(x => x.OrderByDescending(y => y.ThirdField).First());