iOS 9中CPU使用率较高时出现奇怪的UICollectionView错误

Question

In iOS 8 all went well, but with iOS 9 I get this error message: the item height must be less than the height of the UICollectionView minus the section insets top and bottom values, minus the content insets top and bottom values

I have collectionView s embedded into tableView cells. Any idea?

I tried self.automaticallyAdjustsScrollViewInsets = false , but it does not work. DenseMapBase method is get called repeatedly.

Answer 1

automaticallyAdjustsScrollViewInsets is most likely unrelated to this as it affects only the first UIScrollView (or it's descendant like UITableView ) in your view hierarchy. The "automatical scroll view inset adjustment" means that if you have an UINavigationBar in the view, the top content inset of the scroll view is set to the height of the UINavigationBar so that the bar doesn't overlap the scroll content when contentOffset is zero (scrolled to top), but the content can be scrolled under the bar and if the bar is not fully opaque you can see the content through (eg like in Safari).

Please check the cell sizes returned by the delegate of the UICollectionView . That error is printed when the delegate returns a cell size that doesn't fit into the UICollectionView while respecting content and section insets. Your collection view's scroll direction is probably horizontal?

If so then the delegate method probably returns too big height value for the cell. Here's an example:

• UICollectionView has dimensions 100pt x 100pt
• Top and bottom content insets are 5pt
• Top and bottom section insets are 0pt (for simplicity)

The maximum height of the cell in this case would be 100pt - 2 * 5pt = 90pt