title: UICollectionView wrong contentSize on first load, correct after that
body: <p>I have a common UICollectionView with paging and all.</p>
  
  <p>Still trying to figure out why on viewDidLoad:, viewWillAppear: and viewDidAppear: , only on first view call, I get the wrong size when calling myCollectionView.collectionView.contentSize.width. It always respond with 0 width (height is always correct). Successive reload of the view get me the correct one.</p>
  
  <p>Resorted to using </p>
  
  <pre><code>self.collectionView.collectionViewLayout.collectionViewContentSize
  </code></pre>
  
  <p>which give me the correct width event on first load.</p>
  
  <p>Still a mystery to me.</p>