How to set UICollectionViewCell Width and Height p

Question

I am trying to implement a CollectionView. When I am using Autolayout, my cells won't change the size, but their alignment.

Now I would rather want to change their sizes to e.g.

//var size = CGSize(width: self.view.frame.width/10, height: self.view.frame.width/10)

I tried setting in my CellForItemAtIndexPath

collectionCell.size = size

it didn't work though.

Is there a way to achieve this?

edit:

It seems, that the answers will only change my CollectionView width and height itself. Is there are conflict in Constraints possible? Any ideas on that ?

Answer 1

If one is using storyboard and overriding UICollectionViewDelegateFlowLayout then in swift 5 and Xcode 11 also set Estimate size to None

Answer 2

**Swift 5**
To make this work you have to do the following.

Add these protocols

 - UICollectionViewDelegate


 - UICollectionViewDataSource


 - UICollectionViewDelegateFlowLayout

Your code will then look like this

extension YourViewController: UICollectionViewDelegate {
    //Write Delegate Code Here
}

extension YourViewController: UICollectionViewDataSource {
    //Write DataSource Code Here
}

extension YourViewController: UICollectionViewDelegateFlowLayout {
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: screenWidth, height: screenWidth)
    }
}

Now the final and crucial step to see this take effect is to go to your viedDidLoad function inside your Viewcontroller.

    override func viewDidLoad() {
        super.viewDidLoad()
        collection.dataSource = self // Add this
        collection.delegate = self // Add this

        // Do any additional setup after loading the view.
    }

Without telling your view which class the delegate is it won't work.

Answer 3

Try below method

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    return CGSize(width: 100.0, height: 100.0)
}

Answer 4

Finally got the answer. You should extend UICollectionViewDelegateFlowLayout
This should be working with answers above.

Answer 5

in Swift3 and Swift4 you can change cell size by adding UICollectionViewDelegateFlowLayout and implementing it's like this :

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        return CGSize(width: 100, height: 100)
    }

or if create UICollectionView programmatically you can do it like this :

    let layout = UICollectionViewFlowLayout()
                    layout.scrollDirection = .horizontal //this is for direction
                    layout.minimumInteritemSpacing = 0 // this is for spacing between cells
                    layout.itemSize = CGSize(width: view.frame.width, height: view.frame.height) //this is for cell size
let collectionView = UICollectionView(frame: self.view.bounds, collectionViewLayout: layout)

Answer 6

Swift 5 Programmatically

lazy var collectionView: UICollectionView = {
        let layout = UICollectionViewFlowLayout()
        layout.scrollDirection = .horizontal

        //Provide Width and Height According to your need
        let cellWidth = UIScreen.main.bounds.width / 10
        let cellHeight = UIScreen.main.bounds.height / 10
        layout.itemSize = CGSize(width: cellWidth, height: cellHeight)

        //You can also provide estimated Height and Width
        layout.estimatedItemSize = CGSize(width: cellWidth, height: cellHeight)

        //For Setting the Spacing between cells
        layout.minimumInteritemSpacing = 0
        layout.minimumLineSpacing = 0

        return UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
    }()