Persistent UIBarButtonItem in UINavigationBar?

I have an UINavigationController with a UIBarButton to realod something. However, when I push another view on the Navigation Controller, the BarBut开发者_如何学编程tonItem disappears. How can I avoid this? Do I need to add some code in the NavigationController, or set a property for the BarButtonItem?

Thank you.

Add the button to every view controller. It'll still visibly crossfade between them (oh well).

I'm sure there are plenty of hacks you could do (like adding subviews directly to UINavigationBar) but that's likely to break between OS releases.