After looking into it I was surprised to learn that there's no built-in way to underline text in a UI element on iPhone - you have to simply draw it yourself.
Searching the web I found some sample code in varying states of usability. By sticking these together and putting a couple more features in I came up with CVUnderlineButton.
It's available on GitHub at https://github.com/benvium/BVUnderlineButton
Simple example button
Here's the README for the control.
#import "BVUnderlineButton.h" BVUnderlineButton *button = [BVUnderlineButton buttonWithType:UIButtonTypeCustom]; [button addTarget:self action:@selector(aMethod:) forControlEvents:UIControlEventTouchDown]; [button setTitle:@"underlined" forState:UIControlStateNormal]; button.frame = CGRectMake(80.0, 210.0, 160.0, 40.0); [view addSubview:button];
button.underlinePosition = 1;