单击button1时如何快速更改button2的颜色？

Question

All I want to do is change the backgroundColor of fiveMinButton and tenMinButton when fiveMinButton is clicked. Why doesn't this code work? @IBAction will not work either.

@IBOutlet weak var fiveMinButton: UIButton!



 override func viewDidLoad() {
    super.viewDidLoad()

    fiveMinButton.addTarget(self, action: Selector(("action:")), for: UIControlEvents.touchUpInside)

    func action(sender: UIButton){

        if sender === fiveMinButton {

            fiveMinButton.backgroundColor = UIColor.gray
            tenMinButton.backgroundColor = UIColor.lightgray

        }

    }

Answer 1

You are writing the action method inside the viewDidload, Try this:

override func viewDidLoad() {
    super.viewDidLoad()

    fiveMinButton.addTarget(self, action: #selector(action(_:)), for: UIControlEvents.touchUpInside)

}

func action(sender: UIButton){
        if sender == fiveMinButton {
            fiveMinButton.backgroundColor = UIColor.gray
            tenMinButton.backgroundColor = UIColor.lightgray
        }
}

Answer 2

There is 2 problems with your code.

1. The syntax of selector is wrong
2. You have added action of your button inside the viewDidLoad that will also wrong, so write that method outside the viewDidLoad as class method.

For first one change selector like this.

fiveMinButton.addTarget(self, action: #selector(action(sender:)), for: UIControlEvents.touchUpInside)

For second problem just write action out side the viewDidLoad .

Answer 3

If button type rounded rect ..Color cannot be applied. So set the button to type custom and good to go

self.myButton.backgroundColor = UIColor.redColor()

or you can set the background image or image to the button to gain the color

self.myButton.setBackgroundImage(UIImage.imageNamed("myButtonImage.png"), forState: UIControlStateNormal)

or

self.myButton.setImage(UIImage.imageNamed("myButtonImage.png"), forState: UIControlStateNormal)