C# 两行代码实现 延迟加载的单例模式（线程安全）

关键代码第4，5行。

很简单的原理不解释：readonly + Lazy(.Net 4.0 + 的新特性)

     public class LazySingleton
     {
         //Lazy singleton
         private LazySingleton() { Console.WriteLine("Constructing"); }
         private static readonly Lazy<LazySingleton> Linstance = new Lazy<LazySingleton>(() => { return new LazySingleton(); });

         //not lazy Singleton
         //public static readonly LazySingleton instance = new LazySingleton();

         public String Name { get; set; }
         public static LazySingleton Instance { get { return Linstance.Value; } }

         //For test
         public static bool IsValueCreated { get { return Linstance.IsValueCreated; } }
     }

     public class LazySingletonDemo
     {
         public static void Execute()
         {
             Task.Run(() => Foo1());
             //Thread.Sleep(1000);
             Task.Run(() => Foo1());
             Task.Run(() => Foo1());

         }

         public static void Foo1()
         {
             if (!LazySingleton.IsValueCreated)
                 Console.WriteLine("LazySingleton is not initialized");

             LazySingleton.Instance.Name = "HK";

             Console.WriteLine(LazySingleton.Instance.Name);
         }
     }

测试结果：