UICollectionView - When the keyboard appears the entire collection view is shifted with the keyboard

Question

This isn\'t my desired effect. This only happens when the collection view is set to horizontal flow layout. I\'ve seen a few other posts regarding this very same issue but none

Answer 1

Okay so I've found a solution to this problem. I came across this in a couple of other threads on stackoverflow regarding a similar incident, in one case the Answer had no votes attributed to it and a comment left to the answer said it didn't work..

Though after all this I'm still not crystal clear on why the other implementation causes the collection view to shift up. Though there is some correlation between the window, root view controller and it's subviews along with the keyboard. Why this happens I don't know.

Now on to the code and fix..

The main different between the method in the question above and here is the way the collection view is initialised. I'll only post what I changed because the rest is just the same.

AppDelegate.swift

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        let rvc = ViewController()

        window? = UIWindow()
        window?.makeKeyAndVisible()
        window?.rootViewController = rvc
        return true
    }
}

The striking difference here is the root view controller is no longer initialised with the Collection View Controller. We use a standard View Controller.

ViewController.swift

class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {

    lazy var collView: UICollectionView = {
        let layout = UICollectionViewFlowLayout()
        layout.scrollDirection = .horizontal
        let view = UICollectionView(frame: .zero, collectionViewLayout: layout)
        view.dataSource = self
        view.delegate = self
        return view
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        self.view.backgroundColor = UIColor.darkGray
        collView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cellId")
        collView.register(HomeCell.self, forCellWithReuseIdentifier: "homeCellId")
        self.view.addSubview(collView)
        collView.backgroundColor = UIColor.blue
        collView.translatesAutoresizingMaskIntoConstraints = false
        collView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
        collView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor).isActive = true
        collView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor).isActive = true
        collView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true
        collView.heightAnchor.constraint(equalTo: self.view.heightAnchor, multiplier: 1)
        // Do any additional setup after loading the view, typically from a nib.
    }
}

We initialise the View Controller with a collectionview as a subview and apply the same code we would normally to the cells