title: Search in ListView
body: <p>I have a ListView over the whole screen of the application. To search for list items, I want an input field on the top of the ListView, but it should only become visible if the ListView is scrolled down (like the search field in the email application of the iPhone). </p>
  
  <p>Because it is a ListView I can't create a cell with an input field (other field type like the other cells) in it.
  I would be glad if someone can give a hint with which technic I can do it.
  Thx.</p>