代码public sealed class Singleton2{3    static Singleton instance=null;45    Singleton()6    {7    }89    public static Singleton Instance
10    {
11        get
12        {
13            if (instance==null)
14            {
15                instance = new Singleton();
16            }
17            return instance;
18        }
19    }
20}

代码1 public sealed class Singleton2{3    static Singleton instance=null;4    static readonly object padlock = new object();56    Singleton()7    {8    }9
10    public static Singleton Instance
11    {
12        get
13        {
14            lock (padlock)
15            {
16                if (instance==null)
17                {
18                    instance = new Singleton();
19                }
20                return instance;
21            }
22        }
23    }
24}

代码 1public sealed class Singleton2{3    static Singleton instance=null;4    static readonly object padlock = new object();56    Singleton()7    {8    }9
10    public static Singleton Instance
11    {
12        get
13        {
14            if (instance==null)
15            {
16                lock (padlock)
17                {
18                    if (instance==null)
19                    {
20                        instance = new Singleton();
21                    }
22                }
23            }
24            return instance;
25        }
26    }
27}

代码1 public sealed class Singleton2{3    static readonly Singleton instance=new Singleton();45    static Singleton()6    {7    }89    Singleton()
10    {
11    }
12
13    public static Singleton Instance
14    {
15        get
16        {
17            return instance;
18        }
19    }
20}

代码 1 public sealed class Singleton2{3    Singleton()4    {5    }67    public static Singleton Instance8    {9        get
10        {
11            return Nested.instance;
12        }
13    }
14
15    class Nested
16    {
17        static Nested()
18        {
19        }
20
21        internal static readonly Singleton instance = new Singleton();
22    }
23}

using System;
using System.Threading;namespace SigletonPattern.SigletonCounter
{/// <summary>/// 功能：简单计数器的单件模式/// 编写：Terrylee/// 日期：2005年12月06日/// </summary>public class CountSigleton{///存储唯一的实例static CountSigleton uniCounter = new CountSigleton();  ///存储计数值private int totNum = 0;  private CountSigleton() { ///线程延迟2000毫秒Thread.Sleep(2000);} static public CountSigleton Instance() { return uniCounter; } ///计数加1public void Add(){ totNum ++;}  ///获得当前计数值public int GetCounter(){ return totNum;} }
}

using System;
using System.Threading;
using System.Text;namespace SigletonPattern.SigletonCounter
{/// <summary>/// 功能：创建一个多线程计数的类/// 编写：Terrylee/// 日期：2005年12月06日/// </summary>public class CountMutilThread{public CountMutilThread(){}/// <summary>/// 线程工作/// </summary>public static void DoSomeWork(){///构造显示字符串string results = "";///创建一个Sigleton实例CountSigleton MyCounter = CountSigleton.Instance();///循环调用四次for(int i=1;i<5;i++){///开始计数
                MyCounter.Add();results +="线程";results += i.ToString() + "——〉";results += "当前的计数：";results += MyCounter.GetCounter().ToString();results += "\n";Console.WriteLine(results);///清空显示字符串results = "";}}public void StartMain(){Thread thread0 = Thread.CurrentThread; thread0.Name = "Thread 0"; Thread thread1 =new Thread(new ThreadStart(DoSomeWork)); thread1.Name = "Thread 1"; Thread thread2 =new Thread(new ThreadStart(DoSomeWork)); thread2.Name = "Thread 2"; Thread thread3 =new Thread(new ThreadStart(DoSomeWork)); thread3.Name = "Thread 3"; thread1.Start(); thread2.Start(); thread3.Start(); ///线程0也只执行和其他线程相同的工作
            DoSomeWork(); }}
}

using System;
using System.Text;
using System.Threading;namespace SigletonPattern.SigletonCounter
{/// <summary>/// 功能：实现多线程计数器的客户端/// 编写：Terrylee/// 日期：2005年12月06日/// </summary>public class CountClient{public static void Main(string[] args){CountMutilThread cmt = new CountMutilThread();cmt.StartMain();Console.ReadLine();}}
}