UINavigationBar中的UILabel在橫向中被切斷

Question

Swift 5，Xcode 10.2

我想在UINavigationBar顯示兩行文本，這就是為什么我使用UILabel的原因：

@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
}

縱向顯示如下：

在較小的設備上，文字會橫向剪切（在iPhone Xs Max和iPad上很好）：

我試圖按照此處的建議擴展UINavigationBar ：

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

...但沒有進行任何更改並print("Navigationbar height: \\(navigationController!.navigationBar.frame.height)")始終顯示“ 44”，無論它的方向和使用的設備是什么（即使在iPhone X）。

按照此處的建議添加觀察者也無濟於事。

我如何解決此問題以顯示2行代碼，同時又不破壞較大的設備/帶有槽口的設備呢？

Answer 1

我沒有找到使UINavigationBar顯示兩行文本或增加其高度的方法（我在問題中發布的擴展名沒有任何作用）。 相反，我現在使用此代碼根據設備和設備方向更改標簽：

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!
    }
}

標簽示例：

//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!