UIView Swift 4中的边框底部

Question

我有一个UIView，我想在底部添加一个灰色边框，如何快速完成此操作，这是我的新内容。

@IBOutlet weak var viewTopControl: UIView!

Answer 1

如果要通过编程方式进行，则可以将扩展名添加到UIView中，如下所示。

extension UIView {

    enum ViewSide {
        case Left, Right, Top, Bottom
    }

    func addBorder(toSide side: ViewSide, withColor color: CGColor, andThickness thickness: CGFloat) {

        let border = CALayer()
        border.backgroundColor = color

        switch side {
        case .Left: border.frame = CGRect(x: frame.minX, y: frame.minY, width: thickness, height: frame.height); break
        case .Right: border.frame = CGRect(x: frame.maxX, y: frame.minY, width: thickness, height: frame.height); break
        case .Top: border.frame = CGRect(x: frame.minX, y: frame.minY, width: frame.width, height: thickness); break
        case .Bottom: border.frame = CGRect(x: frame.minX, y: frame.maxY, width: frame.width, height: thickness); break
        }

        layer.addSublayer(border)
    }
}

用法示例：

viewTopControl.addBorder(toSide: .Bottom, withColor: UIColor.redColor().CGColor, andThickness: 1.0)