问iOS - UIButton系统选择的图像

EN

  class CustomButton: UIButton {

    /*
    // Only override draw() if you perform custom drawing.
    // An empty implementation adversely affects performance during animation.
    override func draw(_ rect: CGRect) {
        // Drawing code
    }
    */




    override var isSelected: Bool {


        didSet {
            if isSelected {
                self.backgroundColor = UIColor.blue
                self.tintColor = UIColor.white
            } else {
                self.backgroundColor = .white
                self.tintColor = UIColor.red
            }

        }
    }

}

class ViewController: UIViewController {

@IBOutlet weak var button: CustomButton!
override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    button.isSelected = false
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
@IBAction func btnTapped(_ sender: Any) {
    button.isSelected = !button.isSelected
}