CODEWITHSUNDEEP
iosswiftuinavigationcontrollerautolayoutuinavigationbar
noob
noob

Reputation: 555

NavigationBar is hidden when push to another ViewController

I have two viewcontrollers. The first viewcontroller is collection view controller and i set self.navigationController?.hidesBarsOnSwipe = true in viewDidLoad().

When I push the second viewController from the visible cell of collectionView, the navigation bar is showing in the second viewController but if I scroll the collectionView cell and when push the navigation is not showing.

Can anyone tell me what the problem is?

Upvotes: 1

Views: 2740

Answers (4)

zgorawski
zgorawski

Reputation: 2727

scrolling is done via swipe gesture, so it triggers your code:

self.navigationController?.hidesBarsOnSwipe = true

because navigation controller is shared between all view controllers presented on top of it, it's properties (like hidden bar) preserves pushing / popping.

Common pattern is to change it's state in overrided lifecycle methods, eg:

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    self.navigationController?.hidesBarsOnSwipe = false
    self.navigationController?.setNavigationBarHidden(false, animated: true)
}

and reverting those state in viewWillDisappear

Upvotes: 3

isaman kumara
isaman kumara

Reputation: 131

When this property is set to true, an upward swipe hides the navigation bar and toolbar. A downward swipe shows both bars again. If the toolbar does not have any items, it remains visible even after a swipe. The default value of this property is false. (get it from apple)

See the doc https://developer.apple.com/documentation/uikit/uinavigationcontroller/1621883-hidesbarsonswipe

It means when you swipe up it will hide and when swipe down it will shown. That's the reason.

To fix it you can add following code to the other controller 

[self.navigationController setNavigationBarHidden:NO animated:YES];

Upvotes: 1

badhanganesh
badhanganesh

Reputation: 3465

Put this self.navigationController?.hidesBarsOnSwipe = false and this self.navigationController?.setNavigationBarHidden(false, animated: true) in your second view controller.

You might want to move your self.navigationController?.hidesBarsOnSwipe = true from viewDidLoad to viewWillAppear in your first view controller.

Upvotes: 0

technerd
technerd

Reputation: 14504

Don't get much insight what exactly you implemented, but try to unhide navigation bar in second view controller.

Add below code in viewDidLoad method of second View controller.

self.navigationController?.isNavigationBarHidden = false

Upvotes: 0

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