C# Linq-将不同对象的子列表合并到单个对象中

我有一个对象，它有一个日期和一组人，一个人有名字和姓氏。比如：

PeopleInfo
----------
DateTime - StartDate
List<Person> - People

Person
------
string - FirstName
string - LastName

预期产量 在林克这可能吗

谢谢

您可以：

List<PeopleInfo> peopleInfos = ...

var merged = from peopleInfo in peopleInfos
             group peopleInfo by peopleInfo.StartDate into dateGroup
             select new PeopleInfo
             {
                 StartDate = dateGroup.Key,
                 People = dateGroup.SelectMany(pi => pi.People)
                                   .Distinct()
                                   .ToList()
             };

List peopleInfos=。。。
var merged=来自peopleInfos中的peopleInfo
按peopleInfo.StartDate将peopleInfo分组为dateGroup
选择new PeopleInfo
{
StartDate=dateGroup.Key，
People=dateGroup.SelectMany（pi=>pi.People）
.Distinct（）
托利斯先生（）
};

但这看起来真的像一个黑客；我建议您在设计容器类时，首先要防止这种“重复日期”的情况发生。e、 g.

ILookup

或

IDictionary

或

HashSet

的一种实现，它使用

StartDate

表示相等。

ILookup查找=
ILookup<DateTime, Person> lookup =
  (
    from pi in PeopleInfos
    from person in pi.People
    select new {StartDate = pi.StartDate, Person = person }
  ).ToLookup(x => x.StartDate, x => x.Person);

(
来自PeopleInfos中的pi
来自pi中的person。People
选择新{StartDate=pi.StartDate，Person=Person}
).ToLookup（x=>x.StartDate，x=>x.Person）；

或

列表=
(
来自PeopleInfos中的pi
来自pi中的person。People
根据pi.StartDate将人员分组为g
选择new PeopleInfo（）{StartDate=g.Key，People=g.ToList（）}
)托利斯先生（）

谢谢，效果很好。一个更好的实现是一个好主意，但我现在所做的只是暂时的尝试。我同意OP模型还有一些不尽如人意的地方，但是你的解决方案是正确的+1.我要警告的是，虽然这是正确的，但它不必要地展平了整个输入集合，并从头开始分组。不必要的展平？要多少钱？

List<PeopleInfo> peopleInfos = ...

var merged = from peopleInfo in peopleInfos
             group peopleInfo by peopleInfo.StartDate into dateGroup
             select new PeopleInfo
             {
                 StartDate = dateGroup.Key,
                 People = dateGroup.SelectMany(pi => pi.People)
                                   .Distinct()
                                   .ToList()
             };

ILookup<DateTime, Person> lookup =
  (
    from pi in PeopleInfos
    from person in pi.People
    select new {StartDate = pi.StartDate, Person = person }
  ).ToLookup(x => x.StartDate, x => x.Person);

List<PeopleInfo> list =
  (
    from pi in PeopleInfos
    from person in pi.People
    group person by pi.StartDate into g
    select new PeopleInfo() { StartDate = g.Key, People = g.ToList() }
  ).ToList()