iOS 11 Hiding Status Bar pulls my Navigation Controller to the top of the screen

Question

I'm building an application using a UINavigationController embedding a UIPageViewController. In one of the UIPageViewController UIViewControllers, I have a button to display a Photo Gallery, and when showing this modal Photo Gallery UIViewController, I'm hiding the status bar because the Photo Gallery is full screen :

self.present(self.photosViewController!, animated: true, completion: nil)

The problem is that when the transition occurs (the modal UIViewController fades in with a black background), I can see my UINavigationController move up by 20px to the top of the screen, where the Status Bar was.

The problems does not occur when I build on iOS 9.3 or 10.3 simulators, only on iOS 11.0 simulator.

Any way to prevent the IUNavigationController from moving up when hiding the Status Bar?

Answer 1

What I did is to subclass the UINavigationBar class and use it in my UINavigationController (in Storyboard, specify the custom class for the Navigation Bar, under the Navigation Controller) :

class CustomUINavigationBar: UINavigationBar {

    override func layoutSubviews() {
        super.layoutSubviews()

        if (self.frame.origin.y == CGFloat(0)) {
            self.frame.origin.y = CGFloat(20)
        }

        for subView in self.subviews {
            if (subView.className == "_UIBarBackground") {
                subView.frame.size.height = 64
                subView.frame.origin.y = -20
            }
        }
    }

}

The className property comes from :

extension NSObject {
    var className: String {
        return NSStringFromClass(type(of: self))
    }
}