按小组顺序取

Question

我有一个计算比赛结果的web应用程序:

1. 参赛者在几个小时内尝试x次活动(每个活动分配一个分值)。
2. 他们的总分是5个最高分的总和。

我有以下代码在我的控制器。我尝试在几个地方使用.Take(5)，但它返回前5个分数仅，或表中输入的前5个分数。

分组分为几个领域，参赛者按类别(年龄)和性别获奖。我使用一个名为"游戏"的视图模型。我最近一次失败的代码块:

var compdata = from result in db.Results
               where result.Complete == true
               orderby result.Activity.Value descending
               group result by new
               {
                   result.CompetitorId,
                   result.Competitor.Name,
                   result.Competitor.Category,
                   result.Competitor.Gender,
               }
               into resultsGroup
               select new Game
               {
                   CompetitorId = resultsGroup.Key.CompetitorId,
                   Name = resultsGroup.Key.Name,
                   Category = resultsGroup.Key.Category,
                   Gender = resultsGroup.Key.Gender,
                   Score = resultsGroup.Sum(s => s.Activity.Value)
               };

Answer 1

我觉得你快成功了。计算Score值时，需要计算该点的Take(5)值。分组之后。下面的并不是最简洁的方式，但它根据你现在拥有的东西展示了这一点:

Score = resultsGroup.OrderByDescending(s => s.Activity.Value).Take(5).Sum(s => s.Activity.Value)

就得到了类似的结果:

var compdata = from result in db.Results
               where result.Complete == true
               group result by new
               {
                   result.CompetitorId,
                   result.Competitor.Name,
                   result.Competitor.Category,
                   result.Competitor.Gender,
               }
               into resultsGroup
               select new Game
               {
                   CompetitorId = resultsGroup.Key.CompetitorId,
                   Name = resultsGroup.Key.Name,
                   Category = resultsGroup.Key.Category,
                   Gender = resultsGroup.Key.Gender,
                   Score = resultsGroup.OrderByDescending(s => s.Activity.Value).Take(5).Sum(s => s.Activity.Value)
               };