title: Add button "More" to show another button on UITabbarcontroller
body: <p>I want to show more 2 "button" when touch in a tab on "UITabbarController", how can I do that.
  I use UIActionSheet but when I call</p>
  
  <pre><code>[choiceSheet showInView:[self.view window]];
  [choiceSheet showFromTabBar:[[self tabBarController] tabBar]];
  </code></pre>
  
  <p>it show <code>UIActionSheet</code> but still catch excepton.</p>