视图控制器不尊重“largeTitleDisplayMode”

Question

It seems that I can't set navigationItem.largeTitleDisplayMode = .always unless I also set navigationBar.prefersLargeTitles = true ? Is this intended behavior?

I'm having a really hard time believing apple would force me to manually set largeTitleDisplayMode = .never on every screen in the navigation controller, even ones I don't control, in order to get just a single screen to show with large titles.

Answer 1

You can try controlling this via UINavigationControllerDelegate.willShow calls like this.

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        self.navigationController?.delegate = self
    }
}

// Assumption: ViewController is rootViewController for the UINavigationController
extension ViewController: UINavigationControllerDelegate {
    
    func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
        let isRootVC = (viewController === self)
        viewController.navigationItem.largeTitleDisplayMode = isRootVC ? .always : .never
    }
    
}

UPDATE

The other option would be to do this same management on viewWillAppear(_:) & viewWillDisappear(_:) calls for the rootViewController instance in your navigation stack.