Trash can icon animation?

I'm new here and I just had a question about animating the trash can icon in an iPhone application like in the photo and mail app. I tried using the method here to animate the trash icon in a UINavigationController's toolbar, but it didn't seem to do anything.

Can anyone post a code sample of how to use this method correctly? Thanks

-(void)animateToolbarItemIndex:(NSUInteger)index duration:(NSTimeInterval)duration target:(id)target didFinishSelector:(SEL)sele开发者_高级运维ctor;

There is no

-(void)animateToolbarItemIndex:(NSUInteger)index duration:(NSTimeInterval)duration target:(id)target didFinishSelector:(SEL)selector;

method in the official SDK docs. It's likely a private method. Are you working with the official SDK or jailbroken phones?