swift - 单击设置为隐藏在 xcode 中的按钮会在隐藏之前在模拟器中留下一条细线

Question

我是 swift 的新手，所以有点费力想弄清楚发生了什么。这是我的代码片段。我还附上了图片，显示了单击按钮后的外观。任何帮助将不胜感激。谢谢。

@IBOutlet weak var btnOptionOne: UIButton!
@IBOutlet weak var btnOptionTwo: UIButton!
@IBOutlet weak var btnOptionThree: UIButton!

override func viewDidLoad() {
    super.viewDidLoad()
    backgroundColor = view.backgroundColor
    // Do any additional setup after loading the view, typically from a nib.
    card.layer.cornerRadius = 20.0
    frontLabel.layer.cornerRadius = 20.0
    backLabel.layer.cornerRadius = 20.0

    btnOptionOne.layer.cornerRadius = 20.0
    btnOptionOne.layer.borderColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)
    btnOptionOne.layer.borderWidth = 3.0

    btnOptionTwo.layer.cornerRadius = 20.0
    btnOptionTwo.layer.borderColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)
    btnOptionTwo.layer.borderWidth = 3.0

    btnOptionThree.layer.cornerRadius = 20.0
    btnOptionThree.layer.borderColor = #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1)
    btnOptionThree.layer.borderWidth = 3.0

    card.layer.shadowRadius = 15.0
    frontLabel.layer.shadowRadius = 15.0
    backLabel.layer.shadowRadius = 15.0

    card.layer.shadowOpacity = 0.2
    frontLabel.layer.shadowOpacity = 0.2
    backLabel.layer.shadowOpacity = 0.2

    frontLabel.clipsToBounds = true
    backLabel.clipsToBounds = true
}


@IBAction func didTapOnFlashcard(_ sender: Any) {
    if frontLabel.isHidden == true{
        frontLabel.isHidden = false;
    }
    else{
        frontLabel.isHidden = true;
    }
}

@IBAction func didTapOptionOne(_ sender: Any) {
    btnOptionOne.isHidden = true
}

Before clicking on the first option

After clicking on the first option

Answer 1

同时点击移除阴影:-

btnOptionOne.layer.shadowOpacity = 0
btnOptionOne.layer.shadowRadius = 0
btnOptionOne.layer.shadowColor = nil