Error: UICollectionView received layout attributes for a cell with an index path that does not exist in Swift

7
votes

I "https://www.raywenderlich.com/392-uicollectionview-custom-layout-tutorial-pinterest" To create a Custom UICollectionView. (To adjust cell height)

If I scroll up, the cell will continue to be added, and scroll from top to bottom to refresh.

There is no problem when you run your app and initially grow Cells. However, there is always an error when refreshing or reordering the number of cells.

ERROR :

*** Assertion failure in -[UICollectionViewData validateLayoutInRect:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKitCore/UIKit-3698.93.8/UICollectionViewData.m:447

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UICollectionView received layout attributes for a cell with an index path that does not exist :

Therefore, "iOS 10 bug: UICollectionView received layout attributes for a cell with an index path that does not exist" And tried to solve the error.

on the line below

self.artCollectionView.reloadData ()

I tried adding

self.artCollectionView.collectionViewLayout.invalidateLayout ()

but it was not resolved.

Also, I do not know where to run 

cache.removeAll ()

in the prepare () section. (There is a prepare () function in PinterestLayout.swift)

What is the correct way to resolve the error?

4
iosswiftuicollectionview
can you post the full code that you're working with. The error just means when it checks to see how many cells there are its expecting an index number thats beyond the cell count. – Alex Bailey
I've resolved it, but I'll add the source code for everyone. – Enkha

4 Answers

10
votes

There is prepare function in PinterestLayout.swift as it should be because it is the only layout used for customizing the collectionView.

At line 76, in PinterestLayout.swift file.

Try

override public func prepare() {
    cache.removeAll()
    if cache.isEmpty {
       .....
    }
}
3
votes
extension UICollectionView{
   func refreshLayout() {
        let oldLayout = collectionViewLayout as! UICollectionViewFlowLayout
        let newLayout = UICollectionViewFlowLayout()
        newLayout.estimatedItemSize = oldLayout.estimatedItemSize
        newLayout.footerReferenceSize = oldLayout.footerReferenceSize
        newLayout.headerReferenceSize = oldLayout.headerReferenceSize
        newLayout.itemSize = oldLayout.itemSize
        newLayout.minimumInteritemSpacing = oldLayout.minimumInteritemSpacing
        newLayout.minimumLineSpacing = oldLayout.minimumLineSpacing
        newLayout.scrollDirection = oldLayout.scrollDirection
        newLayout.sectionFootersPinToVisibleBounds = oldLayout.sectionFootersPinToVisibleBounds
        newLayout.sectionHeadersPinToVisibleBounds = oldLayout.sectionHeadersPinToVisibleBounds
        newLayout.sectionInset = oldLayout.sectionInset
        newLayout.sectionInsetReference = oldLayout.sectionInsetReference
        collectionViewLayout = newLayout
    }
  }

Then call:

YourCollectionView.refreshLayout()
YourCollectionView.reloadData()

Happy Coding!

3
votes

Received this error when I was accidentally setting a collectionView cell's height to 0. Make sure height (or any dimension) is greater than 0! Making sure it was always greater than 0 solved the issue for me.

1
votes

In my case, because I using same layout(UICollectionViewFLowLayout) object for three collectionViews, so, change to each collectionView using different layout object(create three same new layout), this crash will gone.

我遇到这个问题是因为我对三个 collectionView 使用了同一个 layout，导致 reload 的时候出错，改成每个 collectionView 使用不同 layout 对象就没事了。