小编Yur*_*ick的帖子

当我添加 rightAnchor 约束时，constant= 20 不适用。在leftAnchor就可以了

override init(frame: CGRect) {
    super.init(frame: frame)

    addSubview(collectionView)
    collectionView.translatesAutoresizingMaskIntoConstraints = false
    NSLayoutConstraint.activate([collectionView.leftAnchor.constraint(equalTo: leftAnchor, constant: 20),
                                 collectionView.topAnchor.constraint(equalTo: self.topAnchor),
                                 collectionView.rightAnchor.constraint(equalTo: rightAnchor, constant: 20),
                                 collectionView.heightAnchor.constraint(equalTo: self.heightAnchor)])
}

有人能帮我吗？

我用阴影创建了线圆，但是当我尝试更改时shadowRadius，阴影没有显示

let path = UIBezierPath(ovalIn: rect)
let shapeLayer              = CAShapeLayer()
shapeLayer.path             = path.cgPath
shapeLayer.fillColor        = UIColor.clear.cgColor
shapeLayer.strokeColor      = UIColor.white.cgColor
shapeLayer.lineWidth        = 1
shapeLayer.shadowOpacity    = 0.9
shapeLayer.shadowColor      = UIColor.white.cgColor
shapeLayer.shadowOffset     = .zero
shapeLayer.shadowRadius     = 10.0
//shapeLayer.shadowPath       = path.cgPath

layer.addSublayer(shapeLayer)

具有默认圆角半径的线圆

圆角半径为 10.0 的线圆

有人能帮我吗？