UINavigationBar中的UILabel在横向中被切断

Question

Swift 5，Xcode 10.2

我想在UINavigationBar中显示两行文字，这就是为什么我使用UILabel：

@IBOutlet weak var navigationBar: UINavigationItem!

override func viewDidLoad() {
    let labeltext = NSMutableAttributedString.init(string: "Text in line 1\n(Line 2)")
    labeltext.setAttributes([NSAttributedString.Key.font: UIFont.systemFont(ofSize: 14)],range: NSRange(location: labeltext.length-8, length: 8))
    let label = UILabel()
    label.backgroundColor = .clear
    label.numberOfLines = 2
    label.font = UIFont.boldSystemFont(ofSize: 17.0)
    label.textAlignment = .center
    label.textColor = .black
    label.attributedText = labeltext
    navigationBar.titleView = label
}

在纵向方向上看起来像这样：

在较小的设备上，文本以横向形式被截断（在iPhone Xs Max和iPad上很好）：

我尝试按照建议的here扩展UINavigationBar：

extension UINavigationBar {
    open override func sizeThatFits(_ size: CGSize) -> CGSize {
        let portraitSize = CGSize(width: UIScreen.main.bounds.width, height: 44)
        return portraitSize
    }
}

...但没有做任何更改，print("Navigationbar height: \(navigationController!.navigationBar.frame.height)")始终打印“ 44”，无论它的方向和使用的是什么设备（即使在iPhone X上也是如此）。

按照建议的here添加观察者也无济于事。

如何解决此问题以显示两行代码，同时又不破坏较大的设备/带有缺口的设备呢？

Answer 1

我没有找到一种方法来使UINavigationBar显示两行文本或增加其高度（我在问题中发布的扩展名没有任何作用）。相反，我现在使用此代码根据设备和设备方向更改标签：

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    if (UIDevice.current.orientation == .landscapeLeft || UIDevice.current.orientation == .landscapeRight) && UIDevice.current.userInterfaceIdiom == .phone {
        //1 line: iPhone & horizontal (the NavigationBar on iPads is tall enought to display 2 lines!)
        navigationBar.titleView = labelLandscape!
    } else {
        //2 lines: Vertical (device doesn't matter)
        navigationBar.titleView = labelPortrait!
    }
}

示例标签：

//let labelTextPortrait = NSMutableAttributedString.init(string: "Text in line 1\n(Line 2)")
let labelTextLandscape = NSMutableAttributedString.init(string: "Text in line 1 (Line 2)")
labelTextLandscape.setAttributes([NSAttributedString.Key.font: UIFont.systemFont(ofSize: 14)],range: NSRange(location: labeltextQuer.length-8, length: 8))
//Text size of "(Line 2)" is 8, the remaining text uses 14

var labelLandscape = UILabel()
labelLandscape!.backgroundColor = .clear
labelLandscape!.numberOfLines = 1 //labelPortrait!.numberOfLines = 2
labelLandscape!.font = UIFont.boldSystemFont(ofSize: 17.0)
labelLandscape!.textAlignment = .center
labelLandscape!.textColor = .black
labelLandscape!.attributedText = labelTextLandscape
labelLandscape!.lineBreakMode = .byWordWrapping //important, so it doesn't truncate mid-text!