How to set UICollectionViewCell Width and Height programmatically

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

Answer 1

An other way is to set the value directly in the flow layout

    let layout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
    layout.itemSize = CGSize(width: size, height: size)

Answer 2

swift4 swift 4 ios collection view collectionview example xcode latest code working sample

Add this on Delegate section of the top

UICollectionViewDelegateFlowLayout

and use this function

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
    let width = (self.view.frame.size.width - 20) / 3 //some width
    let height = width * 1.5 //ratio
    return CGSize(width: width, height: height)
}

///// sample complete code

create on collection view and collectionview cell in storyboard give reference to the collection as
@IBOutlet weak var cvContent: UICollectionView!

paste this in View controller

 import UIKit

class ViewController: UIViewController, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {

    var arrVeg = [String]()
    var arrFruits = [String]()
    var arrCurrent = [String]()
    
    @IBOutlet weak var cvContent: UICollectionView!
    
  
    
    override func viewDidLoad() {
        super.viewDidLoad()
        arrVeg = ["Carrot","Potato", "Tomato","Carrot","Potato", "Tomato","Carrot","Potato", "Tomato","Carrot","Potato", "Tomato"]
        
        arrVeg = ["Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange","Mango","Papaya","Orange"]
        
        
        arrCurrent = arrVeg
    }
    //MARK: - CollectionView
    


    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        let width = (self.view.frame.size.width - 20) / 3 //some width
        let height = width * 1.5 //ratio
        return CGSize(width: width, height: height)
    }
    
    func numberOfSections(in collectionView: UICollectionView) -> Int {

        return 1
    }
    
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        
        
        return arrCurrent.count
    }
    
    
    
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath) as! ContentCollectionViewCell
        cell.backgroundColor =  UIColor.green
        return cell
    }
}

Answer 3

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

Answer 4

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)
    }()

Answer 5

So you need to setting from storyboard for attribute for collectionView in cell section estimate Size to none, and in your ViewController you need had delegate method for implementing this method : optional func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize

Answer 6

Use this method to set custom cell height width.

Make sure to add this protocols

UICollectionViewDelegate

UICollectionViewDataSource

UICollectionViewDelegateFlowLayout

If you are using swift 5 or xcode 11 and later you need to set Estimate Size to none using storyboard in order to make it work properly. If you will not set that than below code will not work as expected.

Swift 4 or Later

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)
    }
}

Objective-C

@interface YourViewController : UIViewController<UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout>

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    return CGSizeMake(CGRectGetWidth(collectionView.frame), (CGRectGetHeight(collectionView.frame)));
}