Cell of UICollectionView not always refreshed after a scroll
问题 I have defined in my Storyboard (iPad) a view that contains a UICollectionView , at the bottom of the view there's also a UIToolbar . In the UICollectionView I have added a UICollectionViewCell (implemented by an iPadCellCollectionViewCell class) that contains a another view that is a Core-Plot Graph (a CPTGraphHostingView class). I have a class called X that implements the UICollectionViewDelegate and UICollectionViewDataSource . In the class X, I build for each cell of my view (in