我以编程方式创建的导航控制器不像示例中那样出现

Posted 2023-02-23

【中文标题】我以编程方式创建的导航控制器不像示例中那样出现

【英文标题】：navigation controller that i create programmatically not appearing as in examples

【发布时间】：2019-11-17 03:54:38

【问题描述】：

我正在尝试在我的 swift 项目中创建一个导航控制器。这个时候我只有一个 View Controller，我到处找，想创建导航控制器。我用这些来尝试让它工作： Swift – Instantiating a navigation controller without storyboards in App Delegate

Creating a navigationController programmatically (Swift)

https://www.youtube.com/watch?v=7ZQMv1okhmI

但这些都不适合我。

这是我的 appDelegate：

    import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate 

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool 
        // Override point for customization after application launch.
        self.window = UIWindow(frame: UIScreen.main.bounds)
        let mainVC = ViewController() as UIViewController
        let navigationController = UINavigationController(rootViewController: mainVC)
        navigationController.navigationBar.isTranslucent = false
        self.window?.rootViewController = navigationController
        self.window?.makeKeyAndVisible()
        return true
    

    // MARK: UISceneSession Lifecycle

    func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration 
        // Called when a new scene session is being created.
        // Use this method to select a configuration to create the new scene with.
        return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
    

    func application(_ application: UIApplication, didDiscardSceneSessions sceneSessions: Set<UISceneSession>) 
        // Called when the user discards a scene session.
        // If any sessions were discarded while the application was not running, this will be called shortly after application:didFinishLaunchingWithOptions.
        // Use this method to release any resources that were specific to the discarded scenes, as they will not return.
    

这是我的 ViewController：

import UIKit

class ViewController: UIViewController 

    override func viewDidLoad() 
        super.viewDidLoad()
        view.backgroundColor = .green
    

这是出现在我的模拟器中的内容：

我只是好奇我做错了什么？我查找了几种以编程方式创建导航控制器的方法，它们都以与我上面提供的示例相同的方式结束。

如果还有什么我可以帮助的，请询问，并且请不要标记为重复，因为我知道这个问题之前已经被问过，但这些问题似乎都不适合我。

【参考方案1】：

如果您使用的是 Xcode 11 和 ios 13，则需要在 SceneDelegate.swift 中编写相同的代码。 Apple 将UISceneDelegate 添加到 iOS 13 的主要原因是为多窗口应用程序创建一个良好的入口点。

如果你不打算支持多窗口，你可以从 Info.plist 中删除 SceneDelegate.swift 文件删除 UIApplicationSceneManifest 键并从 AppDelegate.swift 中删除 func application(_: configurationForConnecting:, options:) 和 func application(_:, didDiscardSceneSessions:) 方法

在donnywalls - Understanding the iOS 13 Scene Delegate了解更多关于场景代理的信息