How to add a border to swift navigationBar after removing it

问题

I use:

self.navigationController?.navigationBar.shadowImage = UIImage()

to remove the border of a navigationBar earlier in my app but now I'm not sure to add the border back on a later screen.

回答1:

To reset the navigationBar's shadowImage to the default shadowImage do the following:

self.navigationController?.navigationBar.shadowImage = UINavigationBar().shadowImage

来源：https://stackoverflow.com/questions/57401651/how-to-add-a-border-to-swift-navigationbar-after-removing-it