swift - CAShapeLayer 圆圈在 iPhone 6 上不显示，但它可以使用相同的代码在 iPhone 5 上工作

Question

我在自定义 uiview 类中使用 cashapelayer 以编程方式制作了一个简单的圆圈，如下所示:

class UserProfileCircleAnimated: UIView {

private lazy var leftPhotoArc: CAShapeLayer = {
    let leftPhotoArc = CAShapeLayer()
    leftPhotoArc.lineWidth = 6
    leftPhotoArc.strokeColor = UIColor.rgb(red: 232, green: 72, blue: 85, alpha: 1).cgColor
    leftPhotoArc.fillColor = nil
    leftPhotoArc.path = UIBezierPath(arcCenter: CGPoint(x: 25, y: 25), radius: 25 , startAngle: 2 * CGFloat(M_PI), endAngle: 0, clockwise: true).cgPath
    return leftPhotoArc
}()

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

    translatesAutoresizingMaskIntoConstraints = false
    backgroundColor = UIColor.yellow
    setupViews()
}

private func setupViews(){
    layer.addSublayer(leftPhotoArc)
}
required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}
}

并在自定义 Collection View 单元格中初始化它:

class AllCell: UICollectionViewCell {
let userProfileCircleAnimated = UserProfileCircleAnimated()
override init(frame: CGRect) {
    super.init(frame: frame)
        addSubview(userProfileCircleAnimated)
    userProfileCircleAnimated.centerXAnchor.constraint(equalTo: centerXAnchor).isActive = true
    userProfileCircleAnimated.centerYAnchor.constraint(equalTo: centerYAnchor).isActive = true
    userProfileCircleAnimated.widthAnchor.constraint(equalToConstant: 50).isActive = true
    userProfileCircleAnimated.heightAnchor.constraint(equalToConstant: 50).isActive = true

}
required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}
}

结果是在ip5模拟器上出现，而在ip6上却没有，这是为什么呢？谢谢你! iphone 5 iphone 6

Answer 1

尝试像这样交换开始和结束角度:

leftPhotoArc.path = UIBezierPath(arcCenter: CGPoint(x: 25, y: 25), radius: 25 , startAngle: 0, endAngle: 2 * CGFloat(M_PI), clockwise: true).cgPath

这是合理的，因为你顺时针从 0 移动到 2π。