Обратный таймер

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Timers;
 
namespace ConsoleApplication10
{
  class BackTimer
  {
    private int _time;
    private int _interval;
    private Timer _timer;
 
    public delegate void TimeoutEventHandler(object sender, EventArgs e);
 
    public delegate void TickEventHandler(object sender, int e);
 
    public event TimeoutEventHandler Timeout;
    public event TickEventHandler Tick;
 
    public BackTimer(int time, int interval)
    {
      _timer = new Timer();
 
      _time = time;
      _interval = interval;
 
      _timer.Interval = _interval;
      _timer.Elapsed += Timer_Tick;
    }
 
    private void Timer_Tick(object sender, ElapsedEventArgs e)
    {
      if (_time > 0)
        _time--;
      else
      {
        _timer.Stop();
        Timeout(this, new EventArgs());
      }
      Tick(this, _time);
    }
 
    public void Start()
    {
      _timer.Start();
    }
  }
 
  class Program
  {
    static void Main(string[] args)
    {
      var tmr = new BackTimer(10, 3000);
      tmr.Start();
 
      tmr.Tick += (sender, i) => Console.WriteLine("Time remaining: {0}", i);
      tmr.Timeout += (sender, eventArgs) => Console.WriteLine("Time out.");
 
      Console.ReadKey();
    }
  }
}