代码：

using System;
using System.Collections.Generic;
using System.Dynamic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;namespace Student_c_
{enum Week : int{Mon,Tus,Wed,Thu,Fri,Sat,Sun,}public class Student{public static string Course = "面向对象程序设计！";public static string Where = "G2-407";public string Name { get; set; }public string ClassName { get; set; }private int Id;// 班级的最大容量，这是一个常量  public const int MaxNum = 39;public bool flag = true;// 学生的ID  public int id{get{return Id;}set{if(value >MaxNum||value <0){Console.WriteLine("学号输入错误");flag = !flag;}else{Id = value;}}}// 构造函数  public Student( int id,string name, string className){this.id=id;Name = name;ClassName = className;}internal class Program{public static void GotoClass(Student stu){if(stu.flag){Console.WriteLine("学号是:{2} 班级是：{0} 姓名是：{1}", stu.ClassName, stu.Name, stu.Id);}else{Console.WriteLine(" 班级是：{0} 姓名是：{1}", stu.ClassName, stu.Name);}}static void Main(string[] args){string a, b;int c;string day;Console.WriteLine("输入学号：");c = int.Parse(Console.ReadLine());Console.WriteLine("输入班级：");a = Console.ReadLine();Console.WriteLine("输入姓名：");b = Console.ReadLine();Console.WriteLine("今天是星期几：");day = Console.ReadLine();Console.WriteLine("\n");//   Week worday=(Week)Enum.Parse(typeof(Week), day);if (Enum.TryParse<Week>(day, true, out Week workday))//{if (workday == Week.Sat||workday==Week.Sun){Console.WriteLine("Today is weekend!!!");}else{Console.WriteLine("Today is {0}", day);}}Student stu = new Student(c, b, a);GotoClass(stu);Console.WriteLine($"课程是：{Course} 教室是：{Where}");Console.ReadLine();}}}
}

注意：这里的对应关系