c# - 从 Linq Group By 输出 2 个字段

Question

我想按类上的 WorkGroup.GroupId 属性分组

public class Employee
{
  public int EmployeeID {get; set;}
  public Group WorkGroup {get; set;}
}

但是我需要输出组名属性(可以有重复但在同一个组 ID 之间是相同的)

类似的东西(这当然行不通):

var grps = from emp in Emps
          group emp by emp.WorkGroup.GroupID into g
          select new { GroupID = g.Key, Title = g.Key.WorkGroup.GroupTitle,  Employees = g };

我正在寻找允许我做的输出:

foreach (var g in grps)
{
  Console.WriteLine(g.Title + "-" + g.GroupID);
  foreach (var e in g.Employees)
  {
     Console.WriteLine(e.EmployeeID);
  }
}

Answer 1

只需按 ID 和标题分组:

var grps = 
    from emp in Emps
    group emp by new 
    { 
        GroupID = emp.WorkGroup.GroupID, 
        GroupTitle = emp.WorkGroup.GroupTitle 
    } into g
    select new 
    { 
        GroupID = g.Key.GroupID, 
        GroupTitle = g.Key.GroupTitle,  
        Employees = g
    };