如何在C#中使用Linq计数与group by

Question

我有一个数据表,看起来像这样

基本上我希望它是按列featurename(distinct)分组,它应该在努力和完整列中
指定所有featureid,featurename逗号 分配给comman seprated
的featureid的分别计数 我希望datatable看起来像这样



不知道如何使用计数码

var result5= dtTaskandBugs.AsEnumerable().GroupBy(x => x["Functional Area"])
                               .Select(item => new
                               {
                                   FunctionalArea = item.Key,

                                   Completedsum = item.Sum(y => Convert.ToDecimal(y["Completed"])),
                                   effortsum = item.Sum(z => Convert.ToDecimal(z["effort"])),
                                   storyids = string.Join(",", item.Select(a => a["Storyid"]).Distinct()),
                                   storiesename= string.Join(",", item.Select(b => b["StoryName"]).Distinct()),
                                   Featureid = string.Join(",", item.Select(c => c["Featureid"]).Distinct()),
                                   Featurename= string.Join(",", item.Select(d => d["FeatureName"]).Distinct()),

                               });

Answer 1

只需写入item.count()，您就会得到分组值的计数，