Custom background/transparent background on UIBarButtonItem?

Question

How is this effect achieved? Code snippets are highly welcome.

This can be seen in Notes app and other apps on the App Store.

It seem that either the buttons

Answer 1

If you want to have UIBarButtonItem everywhere in your application, what you can do is in your AppDelegate.m and in your application:didFinishLaunchingWithOptions: method, you can write

[[UIBarButtonItem appearance] setBackgroundImage:[[UIImage alloc] init] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];

This will create an empty image, and it will set UIBarButtonItem's background to that image. With writing it into AppDelegate you will make sure everywhere you are using a UIBarButtonitem it will have transparent background, even your back buttons.