如何将 UIButton 转换为圆形？

Question

我正在尝试将UIButton 设置为圆形，当用户单击它时。但是当我尝试这样做时，我将UIView 的顶部变得平坦。在下面粘贴我的代码。

private enum SignInButtonState {
        case clicked
        case normal
    }


private var currentSignInButtonState: SignInButtonState = .normal
private func updateSignInButton(to state: SignInButtonState) {
        switch state {
        case .clicked:
            signinButton.setTitle("", for: .normal)
            self.currentSignInButtonState = .clicked
            UIView.animate(withDuration: 0.5) {
                self.signinButton.transform = CGAffineTransform(scaleX: self.signinButton.frame.height/self.signinButton.frame.width, y: 1)
                self.signinButton.layer.cornerRadius = self.signinButton.frame.height/2
                
            }
            
        case .normal:
            signinButton.setTitle("Sign In", for: .normal)
            self.currentSignInButtonState = .normal
            UIView.animate(withDuration: 0.5) {
                self.signinButton.transform = CGAffineTransform(scaleX: 1, y: 1)
                self.signinButton.layer.cornerRadius = 5.0
                
            }
        }
    }

我也试过添加

        self.clipsToBounds = true
        self.layer.masksToBounds = true

两者都没有帮助。尝试将形状更改为圆形时添加 UIButton 的图像（黄色按钮）

Answer 1

在您更新后，我发现了您的宽度，问题在于转换，因为它使 .cornerRadius 行为不端，尝试另一种方法可以解决它

• 我可以看到你的宽度 == 查看宽度

所以我们需要创建另一个具有恒定值的宽度约束 并在代码中为两者创建IBOutlets，并在单击时更改每个的优先级并在更改角半径时更改值，请在下方查看

@IBOutlet weak var secondWidthConstant: NSLayoutConstraint! // this is the constant one
@IBOutlet weak var widthOfBtn: NSLayoutConstraint! // this is the one that has == to super.view

  private func updateSignInButton(to state: SignInButtonState) {
    switch state {
    case .clicked:
        signinButton.setTitle("", for: .normal)
        self.currentSignInButtonState = .normal
        widthOfBtn.priority = UILayoutPriority(rawValue: 750) // this one is the constraint that is == to the width of the view
        secondWidthConstant.priority = UILayoutPriority(rawValue: 1000) // this is the constant value constraint
        secondWidthConstant.constant = self.signinButton.frame.height // change the constant after the priorty is set to higher than the == one
        UIView.animate(withDuration: 0.5, animations: {
            self.signinButton.layoutIfNeeded()
            self.signinButton.layer.cornerRadius = (self.signinButton.frame.height / 2)
        }) { (_) in
        }
    case .normal:
        widthOfBtn.priority = UILayoutPriority(rawValue: 1000) //switch back priorty
        secondWidthConstant.priority = UILayoutPriority(rawValue: 750) //switch back priorty
        signinButton.setTitle("Sign In", for: .normal)
        self.currentSignInButtonState = .clicked
        UIView.animate(withDuration: 0.5) {
            self.signinButton.layoutIfNeeded()
            self.signinButton.layer.cornerRadius = 5.0
        }
    }
}