Linq OrderBy取决于条件

本文关键字：条件 取决于 OrderBy Linq | 更新日期: 2023-09-27 18:27:14

我想根据的结果订购一个列表

if(group.Substring(group.Length-1,1)%2==0)

降序else订单递增

List<CellTemp> orderedCells = 
        (from shelf in foundCells
         where Convert.ToInt32(shelf.Group.Substring(shelf.Group.Length - 1), 1) % 2 == 0
         orderby shelf.Grup, shelf.Row descending
         select new CellTemp()
         {
             cod= shelf.cod,
             PN = shelf.PN,
             Description = shelf.Description,
             Group= shelf.Group,
             Row= shelf.Row,
             Shelf= shelf.Shelf
         }).ToList();

我怎样才能保留第一个架子。将OrderBy和OrderBy shelf分组。行升序或降序取决于shelf。群是奇数还是偶数？

shelf.group的格式为"group_A0"。

--------------------编辑-----------------------

很抱歉造成混乱。我想做这样的事。

var orderCells = (from shelf in celuleGasite
  where Convert.ToInt32(shelf.Gruup.Substring(shelf.Group.Length - 1, 1)) % 2 == 0
  orderby shelf.Group, shelf.Row descending
  where Convert.ToInt32(shelf.Group.Substring(shelf.Group.Length - 1, 1)) % 2 == 1
  orderby shelf.Group, shelf.Row ascending 
  select shelf).ToList();

但该列表有0个元素

Linq OrderBy取决于条件

也许这就是您想要的：

 var orderCells = (from shelf in celuleGasite
     where Convert.ToInt32(shelf.Group.Substring(shelf.Group.Length - 1, 1)) % 2 == 0
     orderby shelf.Group, shelf.Row descending)
     .Concat(from shelf in celuleGasite
             where Convert.ToInt32(shelf.Group.Substring(shelf.Group.Length - 1, 1)) % 2 == 1
             orderby shelf.Group, shelf.Row)
     .ToList();

或使用GroupBy:

var orderCells = celuleGasite.GroupBy(shelf=>Convert.ToInt32(shelf.Group[shelf.Group.Length-1]) % 2)
                             .Select(g=>g.Key == 0 ? g.OrderBy(shelf=>shelf.Group)
                                                      .ThenByDescending(shelf=>shelf.Row) :
                                                     g.OrderBy(shelf=>shelf.Group)
                                                      .ThenBy(shelf=>shelf.Row))
                             .SelectMany(x=>x)
                             .ToList();

在King King的帮助下，我设法找到了解决方案。他的代码可能是从头开始写的：）所以如果你像我一样被卡住了，这里是完整的代码。

 var orderCells1 = (from shelf in foundCells
            where Convert.ToInt32(shelf.Group.Substring(shelf.Group.Length - 1, 1)) % 2 == 0
            orderby shelf.Row descending
            select shelf).Concat(from shelf in foundCells
            where Convert.ToInt32(shelf.Group.Substring(shelf.Group.Length - 1, 1)) % 2 == 1
            orderby shelf.Row
            select shelf).OrderBy(grup => grup.Group).ToList();

或使用GroupBy

var orderCells2 = foundCells.GroupBy(shelf=>Convert.ToInt32(shelf.Group[shelf.Group.Length - 1]) % 2)
  .Select(g => g.Key == 0 ? 
               g.OrderByDescending(shelf => shelf.Row) : g.OrderBy(shelf => shelf.Row))
  .SelectMany(x => x).OrderBy(group=>group.Group).ToList();
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