how to create info button on uinavigationbar on iphone

Question

I've seen many of applications that have an info button (the letter "i" with a circle around it) on the uinavigationbar. How do I add this type of button?

Answer 1

The previous answer was close, didn't quite compile. Here's what you really want:

// Info button
UIButton* infoButton = [UIButton buttonWithType:UIButtonTypeInfoLight]; 
[infoButton addTarget:self action:@selector(showInfoView:) forControlEvents:UIControlEventTouchUpInside];
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:infoButton];

Answer 2

There is memory leak in the answer above. You should use "autorelease" to avoid it. I have tried to edit the answer but I wasn't successful so far.

// Info button
UIButton* infoButton = [UIButton buttonWithType:UIButtonTypeInfoLight]; 
[infoButton addTarget:self action:@selector(showInfoView:) forControlEvents:UIControlEventTouchUpInside];
self.navigationItem.leftBarButtonItem = [[[UIBarButtonItem alloc] initWithCustomView:infoButton] autorelease];

THIS IS THE CORRECT WAY TO DO IT.