获取选定的索引标签栏控制器Swift

Question

我正在尝试获取tabbarController的选定索引。

let application = UIApplication.sharedApplication().delegate as AppDelegate
let tabbarController = application.tabBarController as UITabBarController
let selectedIndex = tabBarController.selectedIndex

我收到此错误：'UITabBarController?' does not have a member named 'selectedIndex'

我错过了什么吗？

Answer 1

application.tabBarController是可选的，这意味着它可以是nil。 如果您确定永远不会nil，请执行以下操作：

var selectedIndex = tabBarController!.selectedIndex

Answer 2

你应该试试这个：

let application = UIApplication.shared.delegate as! AppDelegate
let tabbarController = application.window?.rootViewController as! UITabBarController
let selectedIndex = tabbarController.selectedIndex