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

I am currently running OS X Yosemite Developer Preview 7 and Xcode 6 beta 6 targeting iOS 7.1 and following solution works fine for me:

• Create outlet for UINavigationItemand UIBarButtonItems

• Run following code to remove

  [self.navItem setRightBarButtonItem:nil];
  [self.navItem setLeftBarButtonItem:nil];
  

• Run following codes to add buttons again

  [self.navItem setRightBarButtonItem:deleteItem];
  [self.navItem setLeftBarButtonItem:addItem];