ios - 当我没有引用时，如何使用/编辑导航栏功能？

Question

我目前正在学习 iOS 开发，但我很困惑如何在没有 IBOutlet 的情况下编辑/使用导航栏？

代码:

class ChatViewController: UIViewController {

    @IBOutlet weak var tableView: UITableView!
    @IBOutlet weak var messageTextfield: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()
        title = "⚡️FlashChat" //edited the title of the navigation bar for this view
        navigationItem.hidesBackButton = true //hid a button

    }

    @IBAction func sendPressed(_ sender: UIButton) {
    }

    @IBAction func logoutPressed(_ sender: UIBarButtonItem) {
        do {
            try Auth.auth().signOut()
            navigationController?.popToRootViewController(animated: true)
        } catch let signOutError as NSError {
            print ("Error signing out: %@", signOutError)
        }

    }

}

Answer 1

调用setupNavBarAttributes()来自 func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool 的函数位于 Appdelegate.swift 文件中并观察更改。

它将自定义应用程序中每个 UIViewController 的 UINavigationBar。

func setupNavBarAttributes() {

        UINavigationBar.appearance().barStyle = .default
        UINavigationBar.appearance().tintColor = .cyan  // change color of the buttons of navigationbar
        UINavigationBar.appearance().barTintColor = .blue  // change front color of navigationbar
        UINavigationBar.appearance().backgroundColor = .clear
        UINavigationBar.appearance().isTranslucent = true
        UINavigationBar.appearance().shadowImage = UIImage() // make disappear the bottom shadow of navigationbar
        UINavigationBar.appearance().setBackgroundImage(UIImage(), for: .default) // make background to a blank/empty image

        UINavigationBar.appearance().titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.red, NSAttributedString.Key.font: UIFont.systemFont(ofSize: 19, weight: .bold)]  // change the font color of navigation title

    }