CollectionView sizeForItemAtIndexPath never called

Question

This is driving me crazy! I have a UICollectionViewController as shown below:

class PhrasesCompactCollectionViewController: UICollectionViewController


        

Answer 1

Just add: UICollectionViewDelegateFlowLayout

class YourClass: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {}

Answer 2

I had this issue last night. Finally solved it at midnight when I realised 'didSelectItemAtIndex' method was not closed off with a closure bracket "}"

I added a closure bracket at the very bottom of the class when asked by the compile error. So in effect all the methods below 'didSelectItemAtIndex' were inside that method.

Posting here just in case anyone else wastes 4 hours of their evenings on this one :-(

Answer 3

If you're using autolayout, make sure collectionView.translatesAutoresizingMaskIntoConstraints = false is set.

Answer 4

First class need confirm to UICollectionViewDelegateFlowLayout. Then you need to write following code in viewDidLoad():

//To tell the UICollectionView to use your UIViewController's UICollectionViewDelegateFlowLayout methods

collectionView.delegate = self

// If you want to set your own collection view flow layout

let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .vertical //depending upon direction of collection view

self.collectionView?.setCollectionViewLayout(layout, animated: true)

By using this code UICollectionViewDelegateFlowLayout method

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize

will get called, you can set size in this method.

Answer 5

You need to specify that you implement the protocol UICollectionViewDelegateFlowLayout in your class declaration.

class PhrasesCompactCollectionViewController: UICollectionViewController, UICollectionViewDelegateFlowLayout

Answer 6

Use this method

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {

}

Instead of

private func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

}