title: Capture Countdown or Tick Event - Threading.Timer C#
body: <p>I have developed a program using <code>Threading.Timer</code> to call a method after 30 seconds.</p>
  <p>The method is getting called, it's working but I want to get the event so that I can know how many seconds are left out of 30 sec.</p>
  <p>I need a kind of tick event which gets fired every seconds. So that I can show the remaining seconds as well. This is my code:</p>
  <pre><code>Timer timerObj;
  
  timerObj = new Timer(UpdateUI, null, Timeout.Infinite, Timeout.Infinite);
  timerObj.Change(30000, Timeout.Infinite);
  
  
  public void UpdateUI(object state)
  {
      ShowQR= false;
  }
  </code></pre>
  <p>How can I get countdown even ?</p>