C# 包含的集合中的LINQ OrderBy

我正在通过

.Include（ta=>ta.TicketActivities）

检索

Ticket

和

TicketActivities

列表，这是我的

Ticket

类上类型为

ICollection（）

的反向导航属性

如何按

SubmitDate

属性和

TicketActivities

按

DateTime

属性对票据进行排序

 using (var entityContext = new InformationSystemsContext())
 {
     IQueryable<Ticket> tickets = null;
     tickets = entityContext.Tickets.Include(i => i.TicketActivities)
                                    .OrderBy(t => t.SubmitDate).ThenBy(t => t.TicketActivities.DateTime);
 }

使用（var entityContext=new InformationSystemsContext（））
{
IQueryable票证=null；
tickets=entityContext.tickets.Include（i=>i.TicketActivities）
.OrderBy（t=>t.SubmitDate）.ThenBy（t=>t.TicketActivities.DateTime）；
}

var query = (from Ticket in entityContext.Tickets
            join Activity in entityContext.TicketActivities
                on Ticket.ID equals Activity.TicketID into JoinedList // fields you made relationship base on those
            group JoinedList by Ticket into GroupedList
            select new {
                Ticket = GroupedList.Key,
                Activities = GroupedList.OrderBy(u => u.DateTime)
            })
            .OrderBy(u => u.SubmitDate)
            .ToList();