NavBar 上的后退按钮上的字体（Swift）

Question

我可以调整导航栏外观的所有其他方面 - 但“返回”的字体仍然很顽固。

下面的 MWE 显示了我尝试过但无济于事的四件事

1)

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    UIBarButtonItem.appearance().setTitleTextAttributes([NSAttributedString.Key.font: UIFont(name: "Helvetica-Bold", size: 4)!], for: .normal)
    return true
}

2) 3) 4)

类 customNavigationController: UINavigationController {

override func viewDidLoad() {
    super.viewDidLoad()


    UIBarButtonItem.appearance().setTitleTextAttributes(
    [
        NSAttributedString.Key.font : UIFont(name: "Rockwell", size: 4)!,
        NSAttributedString.Key.foregroundColor : UIColor.white,
    ], for: .normal )

    navigationItem.backBarButtonItem?.setTitleTextAttributes([NSAttributedString.Key.font: UIFont(name: "Chalkduster", size: 7)!], for: .normal)

    navigationBar.topItem?.backBarButtonItem?.setTitleTextAttributes([NSAttributedString.Key.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 4)!], for: .normal)
}

}

Answer 1

在 iOS 13 中最简单：

let app = UINavigationBarAppearance()
app.backButtonAppearance.normal.titleTextAttributes = [
    // whatever
]
UINavigationBar.appearance().standardAppearance = app

在 iOS 13 之前，API 不会画出您想要画出的区别。您只需一次为所有后退按钮设置一个单独的栏按钮项标题文本属性。

let title = // ...
let back = UIBarButtonItem(title: title, style: .plain, target: nil, action: nil)
back.setTitleTextAttributes([
    // whatever
], for: .normal)
self.navigationItem.backBarButtonItem = back

（还请记住，当 this 视图控制器可见时，您的后退栏按钮项目不是后退栏按钮项目，但是当 另一个 视图控制器被推到 顶部。）

Answer 2

这个解决方案似乎对我很有效：

// Set all fonts in the navigation controller
class CustomNavigationController: UINavigationController {
    // Font names
    let normalFontName = "AppleSDGothicNeo-Medium"
    let boldFontName = "AppleSDGothicNeo-Bold"

    // Font size
    let fontSize = CGFloat(13)

    // Create fonts
    let backButtonFont = UIFont(name: normalFontName, size: fontSize)
    let titleFont = UIFont(name: boldFontName, size: fontSize)

    override func viewDidLoad() {
        super.viewDidLoad()

        // Set standard appearance
        let appearance = UINavigationBarAppearance()
        appearance.backButtonAppearance.normal.titleTextAttributes = [NSAttributedString.Key.font: backButtonFont]
        appearance.titleTextAttributes = [NSAttributedString.Key.font: titleFont]
        UINavigationBar.appearance().standardAppearance = appearance
    }
}