Cell of UICollectionView not always refreshed after a scroll

Question

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 UICol

Answer 1

I've had a similar issue. I fixed it by forcing a repaint when setFrame: is called on my custom content. In your case, subclass CPTGraphHostingView and override this method:

-(void)setFrame:(CGRect)frame {
    [super setFrame:frame];
    [self setNeedsDisplay]; // force drawRect:
}

Edit: An easier way to refresh cell views when they are reused is to override applyLayoutAttributes: in iPadCellCollectionViewCell as follows:

-(void)applyLayoutAttributes:(UICollectionViewLayoutAttributes *)layoutAttributes {
    // apply custom attributes...
    [self.hostingView setNeedsDisplay]; // force drawRect:
}

Regarding your workaround: there will be more and more subviews in the content view, which probably isn't a good thing. However, if you'd remove any old subview before adding the new one, that should be OK, too.