title: Loop through all controls of a Form, even those in GroupBoxes
body: <p>I'd like to add an event to all TextBoxes on my <code>Form</code>:</p>
  
  <pre><code>foreach (Control C in this.Controls)
  {
      if (C.GetType() == typeof(System.Windows.Forms.TextBox))
      {
          C.TextChanged += new EventHandler(C_TextChanged);
      }
  }
  </code></pre>
  
  <p>The problem is that they are stored in several GroupBoxes and my loop doesn't see them. I could loop through controls of each <code>GroupBox</code> individually but is it possible to do it all  in a simple way  in one loop?</p>