将生成随机背景颜色的按钮 - Xcode - Swift

Question

I'm trying to make a button that will change the background color to a random color. So far I have:

func randomCGFloat() -> CGFloat {
return CGFloat(arc4random()) / CGFloat(UInt32.max)}

extension UIColor {
    static func randomColor() -> UIColor {
        let r = randomCGFloat()
        let g = randomCGFloat()
        let b = randomCGFloat()

        // If you wanted a random alpha, just create another
        // random number for that too.
        return UIColor(red: r, green: g, blue: b, alpha: 1.0)
    }
}

All of this goes outside the view controller because 'extension' is not allowed inside the view controller and must be at file scope.

Then I have this inside the view controller:

 override func viewDidLoad() {
    super.viewDidLoad()
    self.view.backgroundColor = UIColor.randomColor()

For my action button:

@IBAction func changeColor(sender: UIButton) {}

So far the app boots up with a random color. I don't know how to make the action button change the background color to a new random color because background color is outside the scope of my action. I can't put the action outside of the view controller class. The button has to generate a new random color and update the background color.

Answer 1

As long as changeColor is in your view controller, you can just do

@IBAction func changeColor(sender: UIButton) {
    self.view.backgroundColor = UIColor.randomColor()
}

and then you have to connect a touch event of your button (say, touchUpInside) to the action. You can do that in Interface Builder (easy) or in code (trickier, but equally easy when you get the hang of it).