C# Linq Group By 多个字段并返回给实体类List

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;

 namespace study
 {
     class LinqGroup
     {
         static void Main(string[] args)
         {
             List<Employee> empList = new List<Employee>
             {
                new Employee {ID = , FName = "John", Age = , Sex = 'M', Money=},
                new Employee {ID = , FName = "Mary", Age = , Sex = 'F', Money=},
                new Employee {ID = , FName = "Amber", Age = , Sex = 'M', Money=},
                new Employee {ID = , FName = "Kathy", Age = , Sex = 'F', Money=},
                new Employee {ID = , FName = "Lena", Age = , Sex = 'F', Money=},
                new Employee {ID = , FName = "Bill", Age = , Sex = 'M', Money=},
                new Employee {ID = , FName = "Celina", Age = , Sex = 'F', Money=},
                new Employee {ID = , FName = "John", Age = , Sex = 'M', Money=}
             };

             List<Employee> empGroupByList = (from a in empList
                                              group a by new
                                              {
                                                  a.FName,
                                                  a.Sex
                                              } into b
                                              orderby b.Key.FName, b.Key.Sex
                                              select new Employee
                                              {
                                                  FName = b.Key.FName,
                                                  Sex=b.Key.Sex,
                                                  Age = b.Sum(c => c.Age),
                                                  ID = b.Max(c => c.ID),
                                                  Money = b.Average(c => c.Money)
                                              }).ToList<Employee>();
             foreach (var item in empGroupByList)
             {
                 Console.WriteLine("item.ID = " + item.ID);
                 Console.WriteLine("item.FName = " + item.FName);
                 Console.WriteLine("item.Age = " + item.Age);
                 Console.WriteLine("item.Sex = " + item.Sex);
                 Console.WriteLine("item.Money = " + item.Money);
                 Console.WriteLine("------------------------");
             }

             Console.ReadKey();
         }
     }

     public class Employee
     {
         public int ID { get; set; }
         public string FName { get; set; }
         public int Age { get; set; }
         public char Sex { get; set; }
         public decimal Money { get; set; }
     }
 }