How to scale image and center it on a UIButton in Swift? - swift

Question

var button = UIButton.buttonWithType(UIButtonType.Custom) as UIButton
var image = UIImage(named: "myimage.png") as UIImage!
button.frame = CGRectMake(0, 0, 100, 100)
button.setImage(image, forState: .Normal)
I have an image that I've set on my button, but I'd like to scale it to be smaller than the button (for example the image should be 50,50) and center in the button. How might I do this in Swift?

Answer 1

Xcode 8.3.1 • Swift 3.1
let button = UIButton(type: .custom)
let image = UIImage(named: "myimage.png")
func buttonTouchDown(_ button: UIButton) {
print("button Touch Down")
}
override func viewDidLoad() {
super.viewDidLoad()
button.frame = CGRect(x: 0, y: 0 , width: 100, height: 100)
button.backgroundColor = .clear
button.addTarget(self, action: #selector(buttonTouchDown), for: .touchDown)
button.setTitle("Title", for: .normal)
button.setTitleColor(.black, for: .normal)
button.setImage(image, for: .normal)
button.imageEdgeInsets = UIEdgeInsetsMake(25,25,25,25)
view.addSubview(button)
}

Answer 2

Swift 5, Swift 4, Swift 3
var image = UIImage(named: "myimage") as UIImage!
btnetc.setImage(image, for: .normal)
btnetc.imageView?.contentMode = .scaleAspectFill
or
btnetc.imageView?.contentMode = .scaleAspectFit
or
btnetc.imageView?.contentMode = .scaleToFill

Answer 3

Ther is a much easier way to do this where you don't have to deal with content insets. Here its is:
var button = UIButton.buttonWithType(UIButtonType.Custom) as UIButton
var image = UIImage(named: "myimage.png") as UIImage!
button.frame = CGRectMake(0, 0, 100, 100)
button.setImage(image, forState: .Normal)
button.contentMode = .center
button.imageView?.contentMode = .scaleAspectFit

Answer 4

Or via XIB after selecting your UIButton.
Just make sure your insets are all the same.

Answer 5

Xcode 13, Swift 5
Using storyboard, select the button, then in the size inspect click the dropdown on size just above Content inset. There is a list of sizes to select from, and this will adjust your image size(if you use system image). The default size is already set when you added the button on the storyboard to the View Controller.