/* homegrown
 * ..> http://bryanallott.net/
 * the multicast delegate appears to resurrect the
 * observer when an event is fired even if the observer
 * has been disposed
 */
using System;
using System.Collections.Generic;

namespace multicast
{
	public class Subject
	{
		public delegate void EventHandler(string args);
		public event EventHandler FireEvent;
		
		public void OnFireEvent(string e)
		{
			if(null != FireEvent)
				FireEvent(e);
		}
	}
	public class ObserverA : IDisposable
	{
		private bool disposed = false;
		public void Dispose()
		{
			Dispose(true);
			GC.SuppressFinalize(this);
		}
		protected void Dispose(bool disposing)
		{
			if(this.disposed)
				return;
		    disposed = true;
		}
		~ObserverA()
		{
			Dispose(false);
		}
		public void NotifyMe(string args)
		{
			Console.WriteLine(args);
		}
	}
	class MainClass
	{
		public static void Main(string[] args)
		{
			Subject source = new Subject();
			using(ObserverA obsa = new ObserverA())
			{
				source.FireEvent += new Subject.EventHandler(obsa.NotifyMe);
			}
			source.OnFireEvent("fire away!");
		}
	}
}