以编程方式在自定义UITabBarController中导航(Swift)

class CustomTabBarController: UITabBarController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建并设置视图控制器数组
        let viewController1 = UIViewController()
        viewController1.title = "Tab 1"
        viewController1.view.backgroundColor = .red
        
        let viewController2 = UIViewController()
        viewController2.title = "Tab 2"
        viewController2.view.backgroundColor = .green
        
        let viewController3 = UIViewController()
        viewController3.title = "Tab 3"
        viewController3.view.backgroundColor = .blue
        
        self.viewControllers = [viewController1, viewController2, viewController3]
        
        // 设置标签栏项
        let item1 = UITabBarItem(title: "Tab 1", image: nil, selectedImage: nil)
        viewController1.tabBarItem = item1
        
        let item2 = UITabBarItem(title: "Tab 2", image: nil, selectedImage: nil)
        viewController2.tabBarItem = item2
        
        let item3 = UITabBarItem(title: "Tab 3", image: nil, selectedImage: nil)
        viewController3.tabBarItem = item3
    }
}

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // 创建自定义的UITabBarController
    let tabBarController = CustomTabBarController()
    
    // 设置为根视图控制器
    self.window?.rootViewController = tabBarController
    self.window?.makeKeyAndVisible()
    
    return true
}