Get selected index tabbar controller Swift

问题

I'm trying to get the selected index of the tabbarController.

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

I'm getting this error: 'UITabBarController?' does not have a member named 'selectedIndex'

Am I missing something?

回答1:

application.tabBarController is an optional, this means it can be nil. If you are sure it will never be nil, do this:

var selectedIndex = tabBarController!.selectedIndex

回答2:

you should try this:

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

来源：https://stackoverflow.com/questions/28420588/get-selected-index-tabbar-controller-swift