title: Are event handlers guaranteed to run on the UI thread
body: <p>Are event handles like this</p>
  
  <pre><code>notifyIcon.BalloonTipClosed += new EventHandler(delegate(Object sender, EventArgs e)
  {
       // ...
  });
  </code></pre>
  
  <p>guaranteed to run on the UI thread, so I don't need to call <code>Invoke</code> or <code>BeginInvoke</code> methods to update controls?</p>
  
  <p>Thanks in advance.</p>