iPhone hide Navigation Bar only on first page

Question

I have the code below that hides and shows the navigational bar. It is hidden when the first view loads and then hidden when the "children" get called. Trouble is that I cannot find the event/action to trigger it to hide again when they get back to the root view....

I have a "test" button on the root page that manually does the action but it is not pretty and I want it to be automatic.

-(void)hideBar 
{
    self.navController.navigationBarHidden = YES;
}
-(void)showBar 
{       
    self.navController.navigationBarHidden = NO;
}

Answer 1

in Swift 3:

override func viewWillAppear(_ animated: Bool) {
    navigationController?.navigationBar.isHidden = true
    super.viewWillAppear(animated)
}


override func viewWillDisappear(_ animated: Bool) {
    if (navigationController?.topViewController != self) {
        navigationController?.navigationBar.isHidden = false
    }
    super.viewWillDisappear(animated)
}

Answer 2

Swift 4:

In the view controller you want to hide the navigation bar from.

override func viewWillAppear(_ animated: Bool) {
    self.navigationController?.setNavigationBarHidden(true, animated: animated)
    super.viewWillAppear(animated)
}

override func viewWillDisappear(_ animated: Bool) {
    self.navigationController?.setNavigationBarHidden(false, animated: animated)
    super.viewWillDisappear(animated)
}