C#Linq Group By多列

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

class Program
{
    static void Main()
    {
        List<Student> students = new List<Student>
        {
            new Student { Name = "张三", Age = 21, Gender = "男", Score = 80 },
            new Student { Name = "李四", Age = 22, Gender = "男", Score = 90 },
            new Student { Name = "王五", Age = 21, Gender = "女", Score = 85 },
            new Student { Name = "赵六", Age = 23, Gender = "女", Score = 95 },
            new Student { Name = "钱七", Age = 22, Gender = "男", Score = 75 }
        };

        var groupedStudents = from student in students
                              group student by new { student.Age, student.Gender } into g
                              select new
                              {
                                  g.Key.Age,
                                  g.Key.Gender,
                                  Count = g.Count(),
                                  AverageScore = g.Average(s => s.Score)
                              };

        foreach (var student in groupedStudents)
        {
            Console.WriteLine($"Age: {student.Age}, Gender: {student.Gender}, Count: {student.Count}, AverageScore: {student.AverageScore}");
        }
    }
}

class Student
{
    public string Name { get; set; }
    public int Age { get; set; }
    public string Gender { get; set; }
    public int Score { get; set; }
}