如何在UITabBarController中显示新的视图控制器

// 创建一个新的视图控制器
let newViewController = NewViewController()

// 获取UITabBarController的实例
guard let tabBarController = self.tabBarController else {
    return
}

// 创建一个新的UITabBarItem实例
let newItem = UITabBarItem(title: "New", image: UIImage(named: "new_icon"), selectedImage: nil)
newViewController.tabBarItem = newItem

// 将新的视图控制器添加到UITabBarController的viewControllers数组中
var viewControllers = tabBarController.viewControllers ?? []
viewControllers.append(newViewController)
tabBarController.viewControllers = viewControllers

// 设置UITabBarController的selectedViewController属性为新的视图控制器
tabBarController.selectedViewController = newViewController