UITabBar controller gives previous selected index?

问题

I'm using Custom UITabBarController in the app to check selected index. I've this method to trigger when I select the selectedIndex:

override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {

 //   print(self.selectedIndex)

    switch self.selectedIndex {
    case 1:

        print("should load feed " + String(self.selectedIndex))
        (self.viewControllers![1] as?  PageViewController)?.downloadNews()
   case 2:
        print("should load saved" + String(self.selectedIndex))
        (self.viewControllers![2] as? SavedController)?.loadData()
    default:
        return
    }
}

However I get old selected index when I click the new tab bar item. I know it's something easy any idea. Is there a way to takeout the right index in this method?

回答1:

Actually selectedIndex is not changed until didSelect happens. Item index should be taken from the the item itself.

override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem)
{ 
   let indexOfTab = tabBar.items?.index(of: item)
   print("pressed tabBar: \(String(describing: indexOfTab))")
}

来源：https://stackoverflow.com/questions/48192790/uitabbar-controller-gives-previous-selected-index