Still valid for:
iOS 12/Xcode 10/Swift 4.2/OSX 10.13.2
iOS 9.1/Xcode 7.1/Swift 2.1/OSX 10.10.5:
The method titleEdgeInsets didn’t work for me. My button’s frame tightly hugs the text (I didn’t specify a frame size), and the frame has a red background color. After doing:
myButton.titleEdgeInsets = UIEdgeInsetsMake(10,10,10,10)
the red background shrunk inwards by 10 pixels on each side, which meant that now some of the text was outside the red background. Using negative values had no effect on the original frame size.
I was able to get padding around the text, effectively making the frame bigger, by doing:
myButton.contentEdgeInsets = UIEdgeInsetsMake(5,5,5,5)