设计模式(事件)-版本1(简单).txt

C# 是创新性的新式编程语言

线程框架(设计模式)-版本1(简单)
1.CodeFile1.cs

using System;
using System.Collections;
using System.Runtime.CompilerServices;
namespace Movecont
{
	class TypeWithLotsOfEvents
	{
		protected EventHandlerSet eventSet=EventHandlerSet.Synchronized(new EventHandlerSet());
		
		//第一个事件(Foo)定义必要的成员
		protected static readonly object fooEventKey=new object();
		public class FooEventArgs:EventArgs{}
		public delegate void FooEventHandler(object sender,FooEventArgs e);
		public event FooEventHandler Foo
		{
			add{eventSet.AddHandler(fooEventKey,value);}
			remove{eventSet.RemoveHandler(fooEventKey,value);}
		}
		protected virtual void OnFoo(FooEventArgs e)
		{
			eventSet.Fire(fooEventKey,this,e);
		}
		public void SimulateFoo()
		{
			OnFoo(new FooEventArgs());
		}

		//第二个事件(Bar)定义必要的成员
		protected static readonly Object barEventKey=new object();//多个实例是节省内存
		public class BarEventArgs:EventArgs{}
		public delegate void BarEventHandler(Object sender,BarEventArgs e);
		public event BarEventHandler Bar
		{
			add{eventSet.AddHandler(barEventKey,value);}
			remove{eventSet.RemoveHandler(barEventKey,value);}
		} 
		protected virtual void OnBar(BarEventArgs e)
		{
			eventSet.Fire(barEventKey,this,e);
		}
		public void SimulateBar()
		{
			OnBar(new BarEventArgs());
		}

	}
	//寻呼机
	class Pager
	{
		//订阅事件
		public Pager(TypeWithLotsOfEvents mm)
		{
			//(使用了事件,委托,回调方法)
			mm.Bar+=new TypeWithLotsOfEvents.BarEventHandler(PagerMsg);
		}
		//回调方法
		private void PagerMsg(Object sender,TypeWithLotsOfEvents.BarEventArgs e)
		{
			Console.WriteLine("Pagering mail message!");
		}
		//注销事件
		public void Unregister(TypeWithLotsOfEvents mm)
		{
			TypeWithLotsOfEvents.BarEventHandler callback=new TypeWithLotsOfEvents.BarEventHandler(PagerMsg);
			mm.Bar-=callback;
		}
	}

	//管理事件/委托对

	public class EventHandlerSet:IDisposable
	{
		private Hashtable events=new Hashtable();//散列表
		public virtual Delegate this[Object eventKey]//索引器
		{
			get
			{
				return (Delegate)events[eventKey];
			}
			set
			{
				events[eventKey]=value;
			}
		}
		public virtual void AddHandler(Object eventKey,Delegate handler)//添加
		{
			events[eventKey]=Delegate.Combine((Delegate)events[eventKey],handler);
		}
		public virtual void RemoveHandler(Object eventKey,Delegate handler)//移除
		{
			events[eventKey]=Delegate.Remove((Delegate)events[eventKey],handler);
		}
		public virtual void Fire(Object eventKey,object sender,EventArgs e)//触发事件
		{
			Delegate d=(Delegate)events[eventKey];
			if(d!=null)
				d.DynamicInvoke(new object[]{sender,e});
		}
		public void Dispose()//释放资源
		{
			events=null;
		}
		public static EventHandlerSet Synchronized(EventHandlerSet eventHandlerSet)
		{
			if(eventHandlerSet==null)
				throw new ArgumentNullException("eventHandlerSet");
			return new SynchronizedEventHandlerSet(eventHandlerSet);
		}
		//线程安全
		private class SynchronizedEventHandlerSet:EventHandlerSet
		{
			private EventHandlerSet eventHandlerSet;
			public SynchronizedEventHandlerSet(EventHandlerSet eventHandlerSet)
			{
				this.eventHandlerSet=eventHandlerSet;
				Dispose();
			}
			public override Delegate this[Object eventKey]
			{
				[MethodImpl(MethodImplOptions.Synchronized)]
				get
				{
					return eventHandlerSet[eventKey];
				}
				[MethodImpl(MethodImplOptions.Synchronized)]
				set
				{
					eventHandlerSet[eventKey]=value;
				}
			}
			[MethodImpl(MethodImplOptions.Synchronized)]
			public override void AddHandler(Object eventKey,Delegate handler)
			{
				eventHandlerSet.AddHandler(eventKey,handler);
			}

			[MethodImpl(MethodImplOptions.Synchronized)]
			public override void RemoveHandler(Object eventKey,Delegate handler)
			{
				eventHandlerSet.RemoveHandler(eventKey,handler);
			}
			[MethodImpl(MethodImplOptions.Synchronized)]
			public override void Fire(Object eventKey,Object sender,EventArgs e)
			{
				eventHandlerSet.Fire(eventKey,sender,e);
			}
		}		

	}
}

2.主程序

using System;
using System.Collections;
namespace Movecont
{
	/// <summary>
	/// 事件。
	/// </summary>
	class Class1
	{
		/// <summary>
		/// 应用程序的主入口点。
		/// </summary>
		[STAThread]
		static void Main(string[] args)
		{
			TypeWithLotsOfEvents mymail=new TypeWithLotsOfEvents();
			Pager mypager=new Pager(mymail);
			mymail.SimulateBar();

		}
	}
}