UICollectionView Custom Cell to fill width In Swift

Question

I've been trying to figure-out how can i make the cell fill the width, as you can see in the picture the width between the cells is too big. i am using custom cell with only one imageView.

I tried to customize it from the storyboard but i guess there is no option for that or it should be done programmatically.

my UICollectionViewController :

 @IBOutlet var collectionView2: UICollectionView!

    let recipeImages = ["angry_birds_cake", "creme_brelee", "egg_benedict", "full_breakfast", "green_tea", "ham_and_cheese_panini", "ham_and_egg_sandwich", "hamburger", "instant_noodle_with_egg.jpg", "japanese_noodle_with_pork", "mushroom_risotto", "noodle_with_bbq_pork", "starbucks_coffee", "thai_shrimp_cake", "vegetable_curry", "white_chocolate_donut"]

    override func viewDidLoad() {
        super.viewDidLoad()

        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false

        // Do any additional setup after loading the view.

    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        //#warning Incomplete method implementation -- Return the number of sections
        return 1
    }


    override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        //#warning Incomplete method implementation -- Return the number of items in the section
         return recipeImages.count
    }

    override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as! RecipeCollectionViewCell

        // Configure the cell
        cell.recipeImageView.image = UIImage(named: recipeImages[indexPath.row])

        return cell
    }

Answer 1

You need to do this programatically.

Implement UICollectionViewDelegateFlowLayout in your view controller and provide the size in collectionView:layout:sizeForItemAtIndexPath:

func collectionView(_ collectionView: UICollectionView,
                        layout collectionViewLayout: UICollectionViewLayout,
                        sizeForItemAt indexPath: IndexPath) -> CGSize {
        let kWhateverHeightYouWant = 100
        return CGSizeMake(collectionView.bounds.size.width, CGFloat(kWhateverHeightYouWant))
}

You will also want to call collectionView.collectionViewLayout.invalidateLayout() inside your view controller's viewWillLayoutSubviews() so that when the main view's dimensions change (on rotation, for example), the collection view is re-laid out.

Swift 4 Update

func collectionView(_ collectionView: UICollectionView,
                            layout collectionViewLayout: UICollectionViewLayout,
                            sizeForItemAt indexPath: IndexPath) -> CGSize {
            let kWhateverHeightYouWant = 100
            return CGSize(width: collectionView.bounds.size.width, height: CGFloat(kWhateverHeightYouWant))
}