title: UICollectionView - remove all / clean table
body: <p>I have one list of cells(UIView) for use in a UIVIewControll. The UIVIewControll, reads in rows for the CollectionView, from the list depending on a value.</p>
  
  <p>I then have two UICollectionViews showing different cells from the same list of UIViews.</p>
  
  <p>A list oa arrays 1,2,3... is arrays:</p>
  
  <p>-1-<br>
  -3-<br>
  -2-<br>
  -2-<br>
  -2-<br>
  -1-<br></p>
  
  <p>//# Event: open<br>
  CollectionView_ONE then shows all from the list having value 1.<br>
  //# Event: open<br>
  CollectionView_TWO then shows all from the list having value 2.<br>
  //# Event: open<br>
  CollectionView_ONE then shows all from the list having value 3.<br>
  <br>
  The problem is that, I can see the old values from the previous show in example CollectionView_ONE. I do call <code>reloadData</code></p>
  
  <p>Is there any way to clean items in a UICollectionView/UITableView withoug deleting the datasource.</p>