小编phu*_*zzz的帖子

我的非常简单的应用程序遇到了麻烦。

我的应用程序只有两个主要内容，UIViewControllers称为新闻和类别，每个都有自己的UINavigationController.

所以在AppDelegate.swift，我这样做了

window = UIWindow(frame: UIScreen.main.bounds)
let tabBarController = UITabBarController()

let newsVC = NewsVC()

// CREATE TAB BAR ITEM WITH TITLE ONLY
let newsVCTabBarItem = UITabBarItem(title: "News", image: nil, tag: 1)
newsVC.tabBarItem = newsVCTabBarItem

let categoryVC = CategoryVC()

// CREATE TAB BAR ITEM WITH TITLE ONLY
let categoryVCTabBarItem = UITabBarItem(title: "Category", image: nil, tag: 2)
categoryVC.tabBarItem = categoryVCTabBarItem

let rootViewControllers = [newsVC, categoryVC]

// CREATE NAVIGATION CONTROLLER FOR EACH OF THEM
tabBarController.viewControllers = …