Why does UICollectionView log an error when the cells are fullscreen?

Question

I have a UICollectionViewController using a UICollectionViewFlowLayout where my itemSize is the size of the UICollectionView

Answer 1

In my case I have to reduce bottom inset (from 20 to 0) of cell as I have reduced 20 from height of collectionview From

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
-        return UIEdgeInsets(top: 10, left: 10, bottom: 20, right: 10)
+        return UIEdgeInsets(top: 10, left: 10, bottom: 0, right: 10)
     }

func collectionView(_ collectionView: UICollectionView,
                        layout collectionViewLayout: UICollectionViewLayout,
                        sizeForItemAt indexPath: IndexPath) -> CGSize {
        let size = CGSize(width: 350, height: collectionView.bounds.size.height - 20)
        return size
    }

Answer 2

This way had worked for me perfectly!.

I just subtracted the top and bottom insets from the view's height as said in that error.

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    return CGSize(width: view.frame.width , height: view.frame.height - (view.safeAreaInsets.top + view.safeAreaInsets.bottom))
}

I hope it helps!

Answer 3

iOS 11 update: automaticallyAdjustsScrollViewInsets is deprecated in iOS 11.0.

Apple recommends using UIScrollView's contentInsetAdjustmentBehavior method instead. I set this value to .never and the error has gone. You can also set this property in Interface Builder.

Answer 4

ios 10: topmost view was not connected to the view outlet