haperkelu的专栏

    class Light     {         public  virtual void Display()         {             Console.WriteLine("I am light");         }     }     class Window     {         public virtual void Display()         {             Console.WriteLine("I am window

using System; public sealed class Singleton { private static volatile Singleton instance; private static object syncRoot = new Object(); private Singleton() {} public static Singleton Instance { get { if (inst

    public class SingletonFactory where T : new()    {        public static T GetInstance()        {            return SingletonCreator.Instance;        }        private static class SingletonCreator        {            private static  T _instance;