C#实现单件模式的三种常用方法

本文实例讲述了c#实现单件模式的三种常用方法。分享给大家供大家参考。具体分析如下：

单件模式是一种设计模式，即保持同时只能创建一个实例，下面列出了c#实现单件模式的三种方法

方法1

public sealed class singleton
{
  private static readonly singleton instance = new singleton();
  private singleton(){}
  public static singleton instance
  {
  get
  {
   return instance;
  }
  }
}

方法2

public sealed class classicsingleton
{
 private static classicsingleton instance;
 private static object syncroot = new object ();
 private classicsingleton(){}
 public static classicsingleton instance
 {
  get
  {
   if(instance == null)
   {
    lock (syncroot)
    {
     if(instance == null)
     {
      instance = new classicsingleton ();
     }
    }
   }
   return instance;
  }
 }
}

方法3

public class singleton
{
 private static singleton instance;
 // added a static mutex for synchronising use of instance.
 private static system.threading.mutex mutex;
 private singleton(){}
 static singleton ()
 {
  instance = new singleton();
  mutex = new system.threading.mutex();
 }
 public static singleton acquire()
 {
  mutex.waitone ();
  return instance;
 }
 // each call to acquire () requires a call to release()
 public static void release()
 {
  mutex.releasemutex();
 }
}

希望本文所述对大家的c#程序设计有所帮助。