C# 枚举类型

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

namespace ConsoleApplication23
{
    public enum Days { Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday };
    public enum Months : byte { Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec };
    class Program
    {
        static void Main(string[] args)
        {
            Days today = Days.Monday;
            int dayNumber = (int)today;
            Console.WriteLine("{0} is day number #{1}.", today, dayNumber);

            Months thisMonth = Months.Dec;
            byte monthNumber = (byte)thisMonth;
            Console.WriteLine("{0} is month number #{1}.", thisMonth, monthNumber);

            // Output:
            // Monday is day number #1.
            // Dec is month number #11.
            string s = Enum.GetName(typeof(Days), 4);
            Console.WriteLine(s);

            Console.WriteLine("The values of the Days Enum are:");
            foreach (int i in Enum.GetValues(typeof(Days)))
                Console.WriteLine(i);

            Console.WriteLine("The names of the Days Enum are:");
            foreach (string str in Enum.GetNames(typeof(Days)))
                Console.WriteLine(str);



        }
    }
}