Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
756 views
in Technique[技术] by (71.8m points)

swift - iOS 11 large navigation bar title unexpected velocity

I am trying to implement the iOS 11 native large navigation bar title on my new application. By calling below functions in viewDidLoad():

navigationController?.navigationBar.prefersLargeTitles = true navigationController?.navigationItem.largeTitleDisplayMode = .always

I do get what I desired. enter image description here

But, when I start scrolling up (the only view inside the main view is a scroll view), the scrolling makes the large title disappear at a faster velocity than actual scroll with the finger. (that is, if I move 2cm on screen, the scroll view actually scrolls more than 2cm, up until the large title shrinks to the 'usual' size.)

The below is the gif of my app being scrolled. I actually move very little, and it automatically scrolls up that much. This differs from the Apple-made applications (the app store for instance, shown below my app).

Does anyone have solution to solving this abnormal behaviour?

enter image description here

enter image description here

EDIT: Per request, I am adding the current View hierarchy. There isn't anything special in my code, I just set the title and flag for prefersLargeTitles.

enter image description here

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

I solved the problem with these constraints:

    NSLayoutConstraint.activate([
        scrollView.topAnchor.constraint(equalTo: view.topAnchor),
        scrollView.leftAnchor.constraint(equalTo: view.leftAnchor),
        scrollView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
        scrollView.rightAnchor.constraint(equalTo: view.rightAnchor)
        ])

You also have to set this property on your UIViewController subclass:

extendedLayoutIncludesOpaqueBars = YES

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...