title: mouse click event on Tab header in Tabcontrol
body: <p>I have my <code>TabControl</code> made in WPF with C#.  But I display the window like a bar by using window position.  I mean while displaying only tabheader will be display.  My tab header are in the left side.  When I press the tabheader the window width will increse to fit the tab items content.</p>
  
  <p>So I want the click event of tab headers in tabcontrol.  How can I get that?</p>