UICollectionView: must be initialized with a non-nil layout parameter

by

The crash is telling you pretty explicitly what is going wrong:

UICollectionView must be initialized with a non-nil layout parameter.

If you check the documentation for UICollectionView, you’ll find that the only initializer is initWithFrame:collectionViewLayout:. Further, in the parameters for that initializer, you’ll see:

frame

The frame rectangle for the collection view, measured in points. The origin of the frame is relative to the superview in which you plan to add it. This frame is passed to the superclass during initialization.

layout

The layout object to use for organizing items. The collection view stores a strong reference to the specified object. Must not be nil.

I’ve bolded the important part. You must use initWithFrame:collectionViewLayout: to initialize your UICollectionView, and you must pass it a non-nil UICollectionViewLayout object.

One way to fix this, then, would be to simply change the order of initialization you do:

UICollectionViewFlowLayout* flowLayout = [[UICollectionViewFlowLayout alloc] init];
flowLayout.itemSize = CGSizeMake(100, 100);
[flowLayout setScrollDirection:UICollectionViewScrollDirectionHorizontal];
self.collectionView = [[UICollectionView alloc] initWithFrame:self.view.frame collectionViewLayout:flowLayout];
[self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cell"];

Note that in the above example, I’ve assumed you want to use self.view.frame as the frame of self.collectionView. If that’s not the case, insert whatever frame you want instead.

More Related Contents:

  1. Displaying images on another view controller when button is clicked
  2. UICollectionView Self Sizing Cells with Auto Layout
  3. Fatal error: unexpectedly found nil while unwrapping an Optional values [duplicate]
  4. How to make a simple collection view with Swift
  5. Creating a UICollectionView programmatically
  6. UICollectionView inside a UITableViewCell — dynamic height?
  7. UICollectionView, full width cells, allow autolayout dynamic height?
  8. UICollectionView flowLayout not wrapping cells correctly
  9. UICollectionView: Animate cell size change on selection
  10. Dynamic cell width of UICollectionView depending on label width
  11. Long press gesture on UICollectionViewCell
  12. How to center align the cells of a UICollectionView?
  13. ios 8 Swift – TableView with embedded CollectionView
  14. UICollectionView Set number of columns
  15. How to determine height of UICollectionView with FlowLayout
  16. Auto Layout in UICollectionViewCell not working
  17. Auto-layout: What creates constraints named UIView-Encapsulated-Layout-Width & Height?
  18. UICollectionView spacing margins
  19. Snap to center of a cell when scrolling UICollectionView horizontally
  20. UICollectionView – Horizontal scroll, horizontal layout?
  21. iOS 10 bug: UICollectionView received layout attributes for a cell with an index path that does not exist
  22. UICollectionView adding UICollectionCell
  23. Why on Xcode 11, UICollectionViewCell changes size as soon as you scroll (I already set size in sizeForItem AtIndexPath:)?
  24. UIButton in cell in collection view not receiving touch up inside event
  25. UIRefreshControl on UICollectionView only works if the collection fills the height of the container
  26. Aligning right to left on UICollectionView
  27. UIRefreshControl with UICollectionView in iOS7
  28. How to scroll to a particluar index in collection view in swift
  29. UICollectionView auto scroll to cell at IndexPath
  30. Warning: UICollectionViewFlowLayout has cached frame mismatch for index path ‘abc’

Leave a Comment