如何将 UIButton 转换为圆形？

Question

我正在尝试在用户单击时将 UIButton 动画化为圆形。但是当我尝试这样做时，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

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

在你更新后，我发现了你的宽度，问题出在转换中，因为它使 .cornerRadius 行为不正常，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常量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，检查下面的

@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
        }
    }
}

如何将 UIButton 转换为圆形？

How can I transform UIButton to circle?

uiview

ios

swift