C # single case

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;usingSystem.Threading;namespacesingleton{ Public classSingletontest {Private StaticSingletontest Singleton; Private Static ReadOnly ObjectSyncObject =New Object(); /// <summary>        ///The constructor must be private///this way, you cannot use new to create an instance of the class externally./// </summary>        Privatesingletontest () {}/// <summary>        ///define a global access point///set to static method///You can call the method outside of the class without instantiating it/// </summary>        /// <returns></returns>         Public Staticsingletontest Getsingleton () {//this is guaranteed to be instantiated only once//that is, instantiated on the first call//subsequent calls will no longer be instantiated//First heavy Singleton = = NULL            if(Singleton = =NULL)            {                Lock(syncobject) {//Second heavy singleton = = NULL                    if(Singleton = =NULL) {Console.WriteLine (String.Format ("I was created by thread: {0}! ", Thread.CurrentThread.Name)); Singleton=Newsingletontest (); }                }            }            returnSingleton; }    }}

C # single case