How to disable UIBarButtonItem?
Solution 1:
You can disable the left navigation button from inside an UIViewController like this, without using any IBOutlet:
self.navigationItem.leftBarButtonItem.enabled = NO;
To disable the right navigation button:
self.navigationItem.rightBarButtonItem.enabled = NO;
Swift3
self.navigationItem.rightBarButtonItem?.isEnabled = false
Solution 2:
If your toolbar has an IBOutlet (and you've checked to make sure it's non-nil), try:
[ [ [ myToolBar items ] objectAtIndex: myBarButtonItemIndex ] setEnabled:(NO) ];