Use UINavigationControllerDelegate to hide navigation bar in different view controllers.
Assume that you have many kinds of view controllers. Some of them need navigation bar and others don't.
A common solution is to call setNavigationBarHidden in each view controller. Like below:
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
navigationController?.setNavigationBarHidden(true/false, animated: animated)
}
And hide navigation bar when view controller disappears:
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
if isMovingFromParentViewController() // or other logic
{
navigationController?.setNavigationBarHidden(wasNavigationBarHidden, animated: animated)
}
}
But there're a few problems using this solution when it comes to a situation like this:
HideNavigationBarViewController1 is the root view controller in a navigation stack.
HideNavigationBarViewController1 can push to HideNavigationBarViewController2 and ShowNavigationBarViewController1.
HideNavigationBarViewController2 and ShowNavigationBarViewController1 can push to other view controllers just like HideNavigationBarViewController1 do.
It's very complicated to call setNavigationBarHidden every now and then.
When two view controllers of hide-navigation-bar-view-controller come along, the navigation bar will flash when push and pop.
--
UINavigationControllerDelegate is very helpful to do a such thing! EASY.
extension Xxx: UINavigationControllerDelegate {
func navigationController(navigationController: UINavigationController, willShowViewController viewController: UIViewController, animated: Bool) {
switch viewController {
case viewController as HideNavigationBarViewController1, viewController as HideNavigationBarViewController2, viewController as HideNavigationBarViewController3:
navigationController.setNavigationBarHidden(true, animated: animated)
default:
navigationController.setNavigationBarHidden(false, animated: animated)
}
}
}
And one more step to enable the interactive pop gesture that is disabled by setNavigationBarHidden.
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
// http://stackoverflow.com/a/28919337/1573750
// Do this in the root view controller of a navigation controller
navigationController?.interactivePopGestureRecognizer?.delegate = self as? UIGestureRecognizerDelegate
}