DOTA版设计模式——单件模式

单件模式，单件意味着唯一，我们创建的类的实例是唯一的。唯一的处理打印机，消息队列，注册表等等.......
UML图：

单件模式看来简单，其实不然。包括什么双重加锁（多线程要求），延迟实例化等等，具体在TerryLee的blog上有详细的描述，本文不再罗嗦。
单件模式没有公开的构造函数，要实现对象的实例化只能依靠静态的 GetInstance方法。在 GetInstance方法中判断对象是否存在，存在则返回该对象，不存在就实例化一个对象返回。
Dota中时间是唯一的，以下的例子是对白天黑夜的控制，也就是我们的夜魔技能。
测试代码：
            DotaPatternLibrary.Singleton.GameTime gtObj = DotaPatternLibrary.Singleton.GameTime.GetInstance();
            LandpyForm.Form.OutputResult("Game时间类型：" + gtObj.TimeType);
            Thread balanarGamerThread = new Thread(new ThreadStart(BalanarDarkTime));
            Thread akashaGamerThread = new Thread(new ThreadStart(AkashaGetTimeType));
            balanarGamerThread.Start();
            akashaGamerThread.Start();

///   <summary>
         ///  暗夜魔王放大
         ///   </summary>
         public   void  BalanarDarkTime()
        {
            LandpyForm.Form.OutputResult( " 夜魔(Balanar)大招 " );
            DotaPatternLibrary.Singleton.GameTime gtObj  =  DotaPatternLibrary.Singleton.GameTime.GetInstance();
            gtObj.TimeType  =  DotaPatternLibrary.Singleton.TimeTypeValue.Evening;
             for  ( int  i  =   1 ; i  <   5 ; i ++ )
            {
                Thread.Sleep( 2000 );
                LandpyForm.Form.OutputResult( " 时间过去 "   +  i  *   2   +   " 秒 " );
            }
            LandpyForm.Form.OutputResult( " 夜魔(Balanar)大招时间到 " );
            DotaPatternLibrary.Singleton.GameTime gtObjNew  =  DotaPatternLibrary.Singleton.GameTime.GetInstance();
            gtObjNew.TimeType  =  DotaPatternLibrary.Singleton.TimeTypeValue.DayTime;
        }

         ///   <summary>
         ///  痛苦女王获得时间类型
         ///   </summary>
         public   void  AkashaGetTimeType()
        {
             for  ( int  i  =   1 ; i  <   4 ; i ++ )
            {
                Thread.Sleep( 2000 );
                DotaPatternLibrary.Singleton.GameTime gtObj  =  DotaPatternLibrary.Singleton.GameTime.GetInstance();
                LandpyForm.Form.OutputResult( " 痛苦女王(Akasha)获得时间： "   +  gtObj.TimeType);
                Thread.Sleep( 3000 );
            }
        }

完整代码：

using  System;
using  System.Collections.Generic;
using  System.Linq;
using  System.Text;

using  DotaPatternLibrary.Attribute;

namespace  DotaPatternLibrary.Singleton
{
     class  Singleton
    {
         public   static   object  lockObj  =   new   object ();
         private   static  Singleton singleton;

         private  Singleton()
        {
        }

         public   static  Singleton GetInstance()
        {
             lock  (lockObj)
            {
                 if  (singleton  ==   null )
                {
                    singleton  =   new  Singleton();
                }
            }
             return  singleton;
        }
    }

     public   class  TimeTypeValue
    {
         public   const   string  DayTime  =   " DayTime(白天) " ;
         public   const   string  Evening  =   " Evening(夜晚) " ;
    }

     public   class  GameTime
    {
         private   static   object  lockObj  =   new   object ();
         private   static  GameTime gameTime;
         private   string  _timeType;

         public   string  TimeType
        {
             get  {  return  _timeType; }
             set  { _timeType  =  value; }
        }

         private  GameTime()
        {
             this ._timeType  =  TimeTypeValue.DayTime;
        }

         public   static  GameTime GetInstance()
        {
             lock  (lockObj)
            {
                 if  (gameTime  ==   null )
                {
                    gameTime  =   new  GameTime();
                }
            }
             return  gameTime;
        }
    }
}