C＃LINQ：我们可以从GroupBy返回相同的实例，而不是重新进行吗？

Question

I have a collection where I need to group and find max from that group. So I did

var foo = foobar.GroupBy(x => x.Name)
                .Select(x => new Foo { Name = x.Key, Version = x.Max(v => v.Version)))
                .ToList();

If there are say more that 2 properties, is it possible to return same object instead of creating new?

Answer 1

Sure, use OrderByDescending on the group and then First to get the max-version-object:

var maxVersionObjectByName = foobar
    .GroupBy(x => x.Name)
    .Select(grp => grp.OrderByDescending(x => x.Version).First())
    .ToList();