title: IOS: Putting UICollectionViews into UIPageVieControllers
body: <p>In part of my app, I need to have a vertical scrolling apparatus to select levels (for which I'm currently using a collection view for). However I also need to allow the user to swipe left or right to present a new "floor" of levels. For instance there might be 50 levels in one floor and 4 floors. I like the gird-presentation of the collection view, I want the page control capabilities of a UIPageController.</p>
  
  <p>I'm currently managing this (messily) with a blank view controller, into which I load a collection view. And a left swipe reloads this view controller and tells it to load a new collection view.</p>
  
  <p>I don't like this, and I can't figure out how to mesh a collection view into a UIPageController. I think this is the best way to get what I want, but if there's a better approach, let me know.</p>
  
  <p>How do I do this?</p>