How do I show/hide a UIBarButtonItem?

Question

I created a toolbar in IB with several buttons. I would like to be able to hide/show one of the buttons depending on the state of the data in the main window.

Answer 1

Here's a simple approach:

hide:  barbuttonItem.width = 0.01;
show:  barbuttonItem.width = 0; //(0 defaults to normal button width, which is the width of the text)

I just ran it on my retina iPad, and .01 is small enough for it to not show up.