在 Swift 5 中以编程方式在 UITabBarController 中显示视图控制器答案

【问题标题】：Displaying View Controller within a UITabBarController programatically in Swift 5在 Swift 5 中以编程方式在 UITabBarController 中显示视图控制器
【发布时间】：2020-03-27 02:07:12
【问题描述】：

在我的应用程序中，当用户登录时，他们应该被带到一个欢迎屏幕，它是 TabBarController 的一部分。但由于某种原因，当我运行以下几行时，欢迎屏幕 (HomeScreenViewController) 显示底部没有 TabBar 导航按钮。

let homeViewController = self.storyboard?.instantiateViewController(identifier: Constants.Storyboard.homeViewController) as? HomeScreenViewController
self.view.window?.rootViewController = homeViewController
self.view.window?.makeKeyAndVisible()

受另一个 StackOverflow 帖子的启发，我尝试了这个，但也没有用：

let homeController = self.storyboard?.instantiateViewController(identifier:Constants.Storyboard.homeViewController)
(TabBarController.currentInstance?.selectedViewController as?UINavigationController)?.pushViewController(homeController!, animated: true)

作为参考，我的UITabBarController类的名字是TabBarController，标识符可以通过

Constants.Storyboard.tabBarCont

谢谢！

【问题讨论】：

标签： ios swift uitabbarcontroller swift5 xcode11

【解决方案1】：

我想你可以试试这个..

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
            // Override point for customization after application launch.
        window = UIWindow(frame: UIScreen.main.bounds)

        let tabBarController = UITabBarController()

let homeViewController = self.storyboard?.instantiateViewController(identifier: Constants.Storyboard.homeViewController) as? HomeScreenViewController
let anyOtherViewController = self.storyboard?.instantiateViewController(identifier: anyOtherViewController) as? AnyOtherViewController

        homeViewController.tabBarItem = UITabBarItem(title: "Home", image: UIImage(named: "home_image"),tag: 1)
        anyOtherViewController.tabBarItem = UITabBarItem(title: "Other",image:UIImage(named: "other") ,tag:2)
        tabBarController.viewControllers = [homeViewController, anyOtherViewController] 

        window?.rootViewController = tabBarController
        window?.makeKeyAndVisible()
        return true
     }

【讨论】：

【解决方案2】：

登录后这样使用：

let storyboard : UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let centerViewController = storyboard.instantiateViewController(withIdentifier: "tabbar") as! TabBarController
        centerViewController.selectedIndex = 0
        centerViewController.modalPresentationStyle = UIModalPresentationStyle.fullScreen
        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        if let window = UIApplication.shared.windows.first {
            appDelegate.window = window
        }
        appDelegate.window!.rootViewController = centerViewController
        self.present(centerViewController!, animated: false, completion: nil)

【讨论】：