swift - UITableViewCell 中的 UIView 有双边框

Question

使用下面的代码，我添加了一个彩色边框并圆化了传递的角。但是，当我以编程方式调整 UIView 的大小时，旧边框仍然存在，并且我得到了这个双边框:

有人知道如何修复它吗？我尝试调用 cell.layoutSubviews() 和 cell.layer.layoutSublayers()。在设置边框之前，我尝试删除边框图层并将图层设置为nil。似乎没有任何作用。

如果我不调整 View 大小，那就没问题。

func roundCorners (view: UIView, corners: UIRectCorner, radius: CGFloat, color: String) {
    let bounds = view.bounds

    let maskPath = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
    let maskLayer = CAShapeLayer()
    maskLayer.frame = bounds
    maskLayer.path = maskPath.cgPath

    view.layer.mask = maskLayer

    var borderColor = UIColor(red: 0/255.0, green: 0/255.0, blue: 0/255.0, alpha: 1.0)
    switch color {
    case "Green":
        borderColor = UIColor(red: 130/255.0, green: 208/255.0, blue: 151/255.0, alpha: 0.9)
    case "Red":
        borderColor = UIColor(red: 243/255.0, green: 44/255.0, blue: 31/255.0, alpha: 1.0)
        view.alpha = 0.5
    case "Purp":
        borderColor = UIColor(red: 102/255.0, green: 135/255.0, blue: 241/255.0, alpha: 0.7)
    case "DarkBlue":
        borderColor = UIColor(red: 90/255.0, green: 125/255.0, blue: 160/255.0, alpha: 0.6)
    default:
        borderColor = UIColor(red: 150/255.0, green: 150/255.0, blue: 150/255.0, alpha: 0.7)
    }

    let frameLayer = CAShapeLayer()
    frameLayer.frame = bounds
    frameLayer.path = maskPath.cgPath
    frameLayer.strokeColor = borderColor.cgColor
    frameLayer.lineWidth = 3
    frameLayer.fillColor = nil

    view.layer.addSublayer(frameLayer)
}

从cellForRowAt调用:

 roundCorners(view: cell.MoveCellTo_TodayList, corners: [.topLeft, .bottomLeft], radius: 8, color: "Green")

Answer 1

将 maskLayer 和 frameLayer 移出函数的作用域，并在单元格重写的 layoutSubviews 内调用 roundCorners。

var maskLayer: CAShapeLayer!
var frameLayer: CAShapeLayer!

override func layoutSubviews() {
    super.layoutSubviews()

     roundCorners(view: MoveCellTo_TodayList, maskLayer: &maskLayer, frameLayer: &frameLayer, corners: [.topLeft, .bottomLeft], radius: 8, color: "Green")
}

func roundCorners(view: UIView, maskLayer: inout CAShapeLayer, frameLayer: inout CAShapeLayer, corners: UIRectCorner, radius: CGFloat, color: String) {
    let bounds = view.bounds

    let maskPath = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
    if maskLayer == nil {
        maskLayer = CAShapeLayer()
        view.layer.mask = maskLayer

        frameLayer = CAShapeLayer()
        view.layer.addSublayer(frameLayer)
    }

    [...]
}