Linq orderby使用自定义比较器进行两列排序

Question

List<MyObject> objects = (from a in alist
    join b in blist on a.ID equals b.ID
    where a.Number != 4
    orderby b.Rank, a.CustomField
    select a).ToList();

这是我的查询,我想为CustomField属性使用自定义Comparer.有没有办法在双场顺序中做到这一点？

我能够做到这一点:

List<MyObject> objects = objects.OrderBy(a => a.CustomField, new MyComparer<object>())

但我需要它按s.Rank和a.CustomField进行排序.

Answer 1

使用OrderBy()连同ThenBy()您的自定义comparers.

// I'm pretty sure it is not possible to specify
// your custom comparer within a query expression
List<MyObject> objects = (from a in alist
                          join b in blist on a.ID equals b.ID
                          where a.Number != 4
                          select new { a, b })
                         .OrderBy(o => o.b.Rank, new MyRankComparer())
                         .ThenBy(o => o.a.CustomField, new MyComparer<object>())
                         .Select(o => o.a)
                         .ToList();

Answer 2

试试这个:

List<MyObject> objects = objects
    .OrderBy(a => a.Rank)
    .ThenBy(a => 
        a.CustomField, new MyComparer<object>()
    ).ToList();

它首先按Rank字段排序,然后CustomField使用自定义比较器进行排序.