protected void Application_Start(Object sender, EventArgs e)
  {
   init();
   System.Timers.Timer myTimer=new System.Timers.Timer(3000);
   //关联事件
   myTimer.Elapsed += new System.Timers.ElapsedEventHandler(myTimer_Elapsed);
   myTimer.AutoReset = true ;
   myTimer.Enabled = true ;
  }

  private void myTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
  {
   //获取当前时间
   init();
  }
  
  private void init()
  {
   Application.Lock();
   Application["TIMEDEMO"]= DateTime.Now.ToString();
   Application.UnLock();
  }