I have found a great article how to add an Activity Indicator inside Bar Button on Navigation Bar. But I cannot repeat this in my case. I have added both Navigation Bar and UIBarButton in code (not in nib) but I could not find an element named UINavigationButton to put Activity Indicator inside.
I want that UIBarButtonItem button is visible:

And not like that:

Does anyone have a suggestion how to make this work?
A rough work-around could be something like this:
And you’ll get this:
EDIT:
From your comment it seems that you want to add this button inside UIToolbar, not in a UINavigationBar, it’s pretty the same:
and you’ll get this: