How can I show an activity indicator on a UITabBarController

Question

I have a UITabBarController with multiple nav vcs. How can I show an activity indicator on the current visible vc from the tab bar controller's viewDidLoad ?

Answer 1

Objective-C

UIViewController *currentVisibleViewController = [self.tabBarController.viewControllers objectAtIndex:self.tabBarController.selectedIndex];

//Add ActivityIndicator on currentVisibleViewController.view

Swift-3

let currentVisibleViewController = self.tabBarController?.viewControllers?[(self.tabBarController?.selectedIndex)!]
//Add ActivityIndicator on currentVisibleViewController.view