How to add a custom view to a UIBarButtonItem

Swift version: 5.6

Paul Hudson @twostraws May 28th 2019

Most UIBarButtonItems contain either an icon or some text, but they can do so much more – in fact, you can embed any kind of UIView subclass inside a bar button item, then put that button into a navigation bar or toolbar as you normally would.

For example, you can create a UIProgressView and place it into a bar button like this:

var progressView = UIProgressView(progressViewStyle: .default)
progressView.sizeToFit()

let progressButton = UIBarButtonItem(customView: progressView)