在swift 4下更改导航控制器后退按钮的字体

Posted 2023-03-22

【中文标题】在swift 4下更改导航控制器后退按钮的字体

【英文标题】：Change the font on the back button of a navigation controller under swift 4

【发布时间】：2018-02-14 16:07:12

【问题描述】：

Swift 4、ios 11.2.5 Xcode 9.2

尝试更改后退按钮的字体。尝试找到以前的解决方案，但似乎没有一个在 Swift 4、iOS 11.2.5 下使用我的配置、标签栏控制器中的导航控制器。

得到这个代码，第一行和最后一行都可以，但是中间三行不行。

self.navigationController?.navigationBar.titleTextAttributes = [ NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!]
navigationItem.backBarButtonItem?.setTitleTextAttributes([NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!], for: .normal)
navigationItem.backBarButtonItem?.setTitleTextAttributes([NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!], for: .highlighted)
navigationItem.backBarButtonItem?.setTitleTextAttributes([NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!], for: .focused)
navigationItem.title = "Filter \(titleSelection!) [shake to clear]"

这是在viewDidLoad 方法中。这应该有效吗？

【问题讨论】：

我更新了我的答案。

change font of back button on uinavigationcontroller的可能重复

【参考方案1】：

对于 Swift 4，你可以在 AppDelegate 中试试这个。

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool 

        UIBarButtonItem.appearance().setTitleTextAttributes([NSAttributedStringKey.foregroundColor: UIColor.red, NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 15)!], for: UIControlState.normal)

        UIBarButtonItem.appearance().setTitleTextAttributes([NSAttributedStringKey.foregroundColor: UIColor.green, NSAttributedStringKey.font : UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)! ], for: .highlighted)
        UIBarButtonItem.appearance().setTitleTextAttributes([NSAttributedStringKey.foregroundColor: UIColor.blue, NSAttributedStringKey.font : UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)! ], for: .focused)

        return true

在ViewController中。

override func viewWillAppear(_ animated: Bool) 

    self.title = "List"
    self.navigationController?.navigationBar.titleTextAttributes = [ NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!]

    // THE BELOW THREE LINES NOT WORKING.

    //navigationItem.backBarButtonItem?.setTitleTextAttributes([NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!], for: .normal)

    //navigationItem.backBarButtonItem?.setTitleTextAttributes([NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!], for: .highlighted)

    //navigationItem.backBarButtonItem?.setTitleTextAttributes([NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!], for: .focused)

故事板

输出

【讨论】：

对这个也寄予厚望；但不幸的是也没有为我工作。我猜这里有一些奇怪的设置。

是的，这行得通！将代码放入应用程序委托的秘诀似乎！谢谢！！

通过添加到 AppDelegate，这对我来说非常适合整个应用程序。

【参考方案2】：

您可以通过执行以下操作来更改应用程序委托中的字体，这将在整个应用程序中而不是在一个视图控制器中更改字体。

if let customFont = UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20.0) 
    UIBarButtonItem.appearance().setTitleTextAttributes([NSFontAttributeName: customFont], for: .normal)

【参考方案3】：

代替：

navigationItem.backBarButtonItem?.setTitleTextAttributes([NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!], for: .normal)

试试：

self.navigationController?.navigationBar.topItem?.backBarButtonItem?.setTitleTextAttributes([NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!], for: .normal)

【参考方案4】：

在 Swift 5 中，您可以通过以下方式做到这一点：

    let attributes = [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 17, weight: .regular)]
    self.navigationItem.backBarButtonItem?.setTitleTextAttributes(attributes, for: .normal)

请注意，它对下一个推送的视图控制器而不是当前显示的视图控制器有效，这就是为什么它非常混乱！

另外，检查情节提要并选择 previous 视图控制器的导航项，然后在 Back Button（Inspector）中输入一些内容。

【参考方案5】：

要使其在 iOS 13.0 上运行，您应该使用 UINavigationBarAppearience。为了更改导航栏中所有元素的字体，您可以执行以下操作：

if #available(iOS 13.0, *) 
    let navBarAppearance = UINavigationBarAppearance()
    let attributes = [NSAttributedStringKey.font: UIFont(name: "AvenirNextCondensed-DemiBoldItalic", size: 20)!]
    navBarAppearance.titleTextAttributes = attributes
    navBarAppearance.buttonAppearance.normal.titleTextAttributes = attributes
    navBarAppearance.doneButtonAppearance.normal.titleTextAttributes = attributes

    self.navigationController?.navigationBar.scrollEdgeAppearance = navBarAppearance
    self.navigationController?.navigationBar.standardAppearance = navBarAppearance