Clash Royale CLAN TAG#URR8PPP

difference between navigationBar.isHidden and setNavigationBarHidden

I have view controller which I am pushing from a view controller where navigation bar is hidden. But I want to show the navigation bar in destination view controller.

I tried with this statement it was not showing navigationBar.

self.navigationController?.navigationBar.isHidden = false


I tried this statement it is working

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


I want to know what is difference?

3 Answers
3

Nope they are not the same,

self.navigationController?.isNavigationBarHidden

self.navigationController?.isNavigationBarHidden

is a getter property (it shows you wheather the navBar is hidden or not.) It will just return a boolean value conveying the state of the NavBar weather it is hidden or not.
(try assigning its value to bool like var isHidden = self.navigationController?.isNavigationBarHidden it will give you true of false according to state to the NavBar.)

var isHidden = self.navigationController?.isNavigationBarHidden

whereas
self.navigationController?.setNavigationBarHidden(false, animated: true)

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

is a setter propety which gives you the provision of setting the state of the navBar.

Compiler does not throw any error on self.navigationController?.isNavigationBarHidden = false
but will not do anything as you can only know the state from here.

self.navigationController?.isNavigationBarHidden = false

isNavigationBarHidden

setNavigationBarHidden

isNavigationBarHidden = true

setNavigationBarHidden(true, animated: false)

navigationBar.isHidden

Effect is exactly the same, but when using second version (method) you can also define animation.

When you are doing it via property - animation is off by default.

On top of that you have another option:

self.navigationController?.isNavigationBarHidden = false


More on that topic here:
https://developer.apple.com/documentation/uikit/uinavigationcontroller/1621850-isnavigationbarhidden

If true, the navigation bar is hidden. The default value is false. Setting this property changes the visibility of the navigation bar without animating the changes. If you want to animate the change, use the setNavigationBarHidden(_:animated:)method instead.

.isHidden and setNavigationBarHidden() have different effects and outcomes. We won't be talking about the animated part.

.isHidden

setNavigationBarHidden()

The property of self.navigationController?.navigationBar.isHidden is an extension from UIView. The isHidden property belongs to UIView that means that navigationBar (which extends UIView) had done some overriding in isHidden causing it to have different effect and outcome compared to setNavigationBarHidden().

self.navigationController?.navigationBar.isHidden

UIView

isHidden

UIView

navigationBar

UIView

isHidden

setNavigationBarHidden()

Example for setNavigationBarHidden(true):

setNavigationBarHidden(true)

where the navigationBar won't be transparent and page 1 (page with navigationBar hidden).

Example for .isHidden = true:

where the navigationBar is fully transparent and page 1 is displayed under page 2's navigationBar. Number 3 is the UIWindow.

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