UICollectionViewCell shadow causes small lag

Question

When scrolling down in my UICollectionView it lags, and caused by this:

imageCell?.backgroundColor = UIColor.whiteColor()
imageCell?.layer.masksToBounds = false
imageCell?.layer.shadowOpacity = 0.5
imageCell?.layer.shadowRadius = 5.0
imageCell?.layer.shadowOffset = CGSizeZero
imageCell?.layer.shadowColor = UIColor.grayColor().CGColor

imageCell is the cell name:

let imageCell = collectionView.dequeueReusableCellWithReuseIdentifier("imageCell", forIndexPath: indexPath) as? CollectionViewCell

Any suggestions what i should do?

Did you create a cell in Interface Builder with a identifier of imageCell or is it all done in code? — Jay, Dec 21 '15 at 23:09
Did you find a solution to this? I ran into the similar issue — JayVDiyk, Feb 24 '16 at 05:51
@JayVDiyk I removed the shadow. Looks more professional without shadow also. — Roduck Nickes, Mar 17 '16 at 22:47

Caleb · Answer 1 · 2015-12-21T23:46:52.780

1

When using shadows, it is a good idea to specify the shadowPath if you know the shape.

imageCell?.layer.shadowPath = UIBezierPath(rect: imageCell?.frame ?? CGRectZero).CGPath

Apple mentions

Specifying an explicit path usually improves rendering performance.

edited Dec 21 '15 at 23:46

answered Dec 21 '15 at 23:01

Caleb

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score 0 · Answer 2 · edited May 23 '17 at 10:27

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I ran into this same thing when I was using images that were too big. I converted then to .png and made them smaller - that helped. (not sure if you are using any images).

But the thing that really made a difference was rasterizing

cell.layer.shouldRasterize

edited May 23 '17 at 10:27

Community

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answered Dec 22 '15 at 00:05

Jay

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UICollectionViewCell shadow causes small lag

2 Answers2