Shrink large title when scrolling (not UITableViewController) iOS 11

Question

I have got a View Controller embedded in a Navigation Controller with prefers large titles option set to true; inside the View Controller there’s a Scroll View.

I wa

Answer 1

Setting prefersLargeTitles in code did work for me to make the NavBar title shrink and grow as you scroll. I did notice if you set the property through InterfaceBuilder, the shrinking feature didn't work.

Instead set in code like

    self.navigationController?.navigationBar.prefersLargeTitles = true

Answer 2

If u have problem collapse root navigationBar from presented VC's scrollView, can try this: Add UIScrollView to RootVC. Important - UIScrollView must be root view(at index 0). In presentedVC we can use scrollViewDidScroll and set offset on our root UIScrollView. see here with gif and code RootVC view hierarchy: screenshot (sorry for link, not enough reputation)

in presentedVC try this

func scrollViewDidScroll(_ scrollView: UIScrollView) {
        if #available(iOS 11.0, *) {
            let offset = scrollView.contentOffset
            rootVC.scrollView.contentOffset = offset
        }
}

Answer 3

You need to:

1. Pin scroll top view to super view top

2. Add

override func viewDidLoad() {
    super.viewDidLoad()

    scrollView?.alwaysBounceVertical = true
  }

Answer 4

I used dsk1306 solutions, see above. But in my case I had a WebView in the UIViewController with the large title.

So I had to set the UIWebView ScrollView delegate:

self.webView.scrollView.delegate = self

and

extension MyViewController: UIScrollViewDelegate {

func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {
    if #available(iOS 11.0, *) {
        UIView.animate(withDuration: 0.5, animations: {
            self.navigationController?.navigationBar.prefersLargeTitles = (velocity.y < 0)
        })
    }
}

}

Answer 5

I had the similar problem, is was because of many UIScrollView-based view inside view controller and I was scrolling not first in hierarchy. Once it's only one it works fine with UIScrollView, WKWebView or UITextView without any line of code.

Answer 6

Have you tried something like this? It converts the large title display mode when the content is scrolled up.

class P1ViewController: UIViewController, UIScrollViewDelegate
{
    var canTransitionToLarge = false
    var canTransitionToSmall = true    

    func scrollViewDidScroll(_ scrollView: UIScrollView)
    {
        if canTransitionToLarge && scrollView.contentOffset.y <= 0 {
            UIView.animate(withDuration: 0.5) {
                self.navigationItem.largeTitleDisplayMode = .always
            }
            canTransitionToLarge = false
            canTransitionToSmall = true
        }
        else if canTransitionToSmall && scrollView.contentOffset.y > 0 {
            UIView.animate(withDuration: 0.5) {
                self.navigationItem.largeTitleDisplayMode = .never
            }
            canTransitionToLarge = true
            canTransitionToSmall = false
        }
    }
}