UICollectionView fails to honour zPosition and zIndex - iOS 11 only
Originator: | foundry.tv | ||
Number: | rdar://34308893 | Date Originated: | 7 September 2017 |
Status: | Open | Resolved: | |
Product: | ios + SDK | Product Version: | ios 11 |
Classification: | Reproducible: | Yes |
Area: UIKit Summary: Zindex and ZPosition are not honoured in CollectionView headers Steps to Reproduce: Set up a collectionView with a header and cells. Set the zPosition or zIndex of the header to position it below the level of the cells. Expected Results: Header is positioned below the level of the cells Actual Results: Header is positioned above the level of the cells, as if the zIndex or zPosition had not been changed Workaround: Add a small delay before setting the zPosition (0.35s seems to work) Version/Build: This only occurs on iOS11 and only if building with XCode 9 Tested on XCode 9 beta 5 and XCode 9 beta 6. Simulator (SE and 6 tested) and Device (SE / ios11 beta).
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A better workaround...
A better around is suggested in this StackOverflow reply:
"Set the header view layer's zPosition in willDisplaySupplementaryView".
No need to mess with hacky timers.
it seems fixed in iOS 11.1
I am still seeing the issue on iPad Air 2 (11.1.2), iPhone SE (11.2-beta 15C5110b))
update: building with XCode 9 GM and running on ios11 GM exhibits the same bug