swift - 如何缩放图像并将其置于 Swift 中的 UIButton 中心？

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)

我在按钮上设置了一张图片，但我想将其缩放为小于按钮(例如图片应为 50,50)并居中放置在按钮上。我如何在 Swift 中执行此操作？

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)
}