Nullable<>基础应用

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

namespace NullableDemo
{
    class Employee
    {
        private string name;

        public string Name
        {
            get { return name; }
            set { name = value; }
        }

        private bool isMarried;   

        public bool IsMarried
        {
            get { return isMarried; }
            set { isMarried = value; }
        }

        // marriedTime实际上还是一个DateTime类型
        private Nullable<DateTime> marriedTime;

       public Nullable<DateTime> MarriedTime
        {
            get
            {
                return this.marriedTime;
            }
            set
            {
                if (!this.isMarried)
                    this.marriedTime = null;
                else
                    this.marriedTime = value;
            }
        }

        public Employee(string name, bool ismarried)
        {
            this.name = name;
            this.isMarried = ismarried;      
        }

        public void ShowInfo()
        {
            Console.WriteLine("Name:{0}", this.Name);
            Console.WriteLine("Married:{0}", this.isMarried ? "Yes" : "No");
            if (this.MarriedTime.HasValue)
            {
                Console.WriteLine("Anniversary:{0:MMMM d}", this.MarriedTime);
            }
            else
            {
                Console.WriteLine("Anniversary:none");
            }
        }

        static void Main(string[] args)
        {
            Employee e1 = new Employee("Tom", true);
            e1.marriedTime = Convert.ToDateTime("1990-1-1");
            e1.ShowInfo();

            Employee e2 = new Employee("Lily", false);
            e2.ShowInfo();

            Console.ReadLine();
        }
    }
  
}