Question

我在向堆栈视图添加右上角和左上角按钮时出现问题。通过界面构建器添加的按钮，然后由扩展名舍入，将呈现，但是如果通过代码添加按钮则不会。可能还有一些IB适用的附加属性。

以下是代码的摘录，说明了问题。

import UIKit

class TestViewController: UIViewController {
let colorDictionary = ["Red":UIColor(red: 1.0, green: 0.0, blue: 0.0, alpha: 1.0),"Green":UIColor(red: 0.0, green: 1.0, blue: 0.0, alpha: 1.0),"Blue":UIColor(red: 0.0, green: 0.0, blue: 1.0, alpha: 1.0),]

func colorButton(withColor color:UIColor, title:String) -> UIButton{
    let newButton = UIButton(type: .system)
    newButton.backgroundColor = color
    newButton.setTitle(title, for: .normal)
    newButton.setTitleColor(UIColor.white, for: .normal)

    //Buttons fail to render if roundedButton() is applied
    //**************************
    //newButton.roundedButton()
    //**************************
    return newButton
}


override func viewDidLoad() {
    super.viewDidLoad()
    displayButtonsInStackView()
}

func displayButtonsInStackView(){
    //generate an array

    var buttonArray = [UIButton]()
    for (myKey,myValue) in colorDictionary{
        buttonArray += [colorButton(withColor: myValue, title: myKey)]
    }

     let stackView = UIStackView(arrangedSubviews: buttonArray)
     stackView.axis = .horizontal
     stackView.distribution = .fillEqually
     stackView.alignment = .fill
     stackView.spacing = 5
     stackView.translatesAutoresizingMaskIntoConstraints = false
     view.addSubview(stackView)

    //autolayout the stack view - pin 30 up 20 left 20 right 30 down
    let viewsDictionary = ["stackView":stackView]
    let stackView_H = NSLayoutConstraint.constraints(withVisualFormat: "H:|-20-[stackView]-20-|", options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: viewsDictionary)
    let stackView_V = NSLayoutConstraint.constraints(withVisualFormat: "V:|-30-[stackView]-30-|", options: NSLayoutFormatOptions(rawValue:0), metrics: nil, views: viewsDictionary)
    view.addConstraints(stackView_H)
    view.addConstraints(stackView_V)
    }
}

extension UIButton {

    func roundedButton(){
    let maskPath = UIBezierPath(roundedRect: self.bounds,
                                byRoundingCorners: [.bottomRight , .topRight],
                                cornerRadii:CGSize(width:8.0, height:8.0))
    let maskLayer = CAShapeLayer()
    maskLayer.frame = self.bounds
    maskLayer.path = maskPath.cgPath
    self.layer.mask = maskLayer
    }
}

Answer 1

问题是你的按钮没有尺寸。改变这个：

// ...
newButton.setTitleColor(UIColor.white, for: .normal)
newButton.roundedButton()
// ...

到此：

// ...
newButton.setTitleColor(UIColor.white, for: .normal)
newButton.sizeToFit()
newButton.roundedButton()
// ...

如何应用以编程方式添加到StackView的按钮的圆角

1 个答案: