UIView Swift 4中的边框底部答案

【问题标题】：Border bottom in UIView Swift 4UIView Swift 4中的边框底部
【发布时间】：2018-12-24 03:05:53
【问题描述】：

我有一个 UIView，我想在底部添加一个灰色边框，我该如何快速做到这一点，我是新手。

@IBOutlet weak var viewTopControl: UIView!

【问题讨论】：

【解决方案1】：

如果你想通过编程来实现，你可以向 UIView 添加扩展，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)
    }
}

示例用法：

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

【讨论】：

【解决方案2】：

这是为任何 UIView 子类创建边框的通用 Swift 扩展：

extension UIView {
 func addTopBorderWithColor(color: UIColor, width: CGFloat) {
    let border = CALayer()
    border.backgroundColor = color.cgColor
    border.frame = CGRect(x: 0, y: 0, width: self.frame.size.width, height: width)
    self.layer.addSublayer(border)
}

func addRightBorderWithColor(color: UIColor, width: CGFloat) {
    let border = CALayer()
    border.backgroundColor = color.cgColor
    border.frame = CGRect(x: self.frame.size.width - width, y: 0, width: width, height: self.frame.size.height)
    self.layer.addSublayer(border)
}

func addBottomBorderWithColor(color: UIColor, width: CGFloat) {
    let border = CALayer()
    border.backgroundColor = color.cgColor
    border.frame = CGRect(x: 0, y: self.frame.size.height - width, width: self.frame.size.width, height: width)
    self.layer.addSublayer(border)
}

func addLeftBorderWithColor(color: UIColor, width: CGFloat) {
    let border = CALayer()
    border.backgroundColor = color.cgColor
    border.frame = CGRect(x: 0, y: 0, width: width, height: self.frame.size.height)
    self.layer.addSublayer(border)
    }
 }

【讨论】：

【解决方案3】：

这里有另一个版本

import UIKit

extension UIView {

    // Example use: myView.addBorder(toSide: .Left, withColor: UIColor.redColor().CGColor, andThickness: 1.0)

    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: self.frame.origin.x, y: self.frame.origin.y, width: thickness, height: self.frame.size.height)
        case .right: border.frame = CGRect(x: self.frame.size.width - thickness, y: self.frame.origin.y, width: thickness, height: self.frame.size.height)
        case .top: border.frame = CGRect(x: self.frame.origin.x, y: self.frame.origin.y, width: self.frame.size.width, height: thickness)
        case .bottom: border.frame = CGRect(x: self.frame.origin.x, y: self.frame.size.height - thickness, width: self.frame.size.width, height: thickness)
        }
        self.layer.addSublayer(border)
    }
}

示例用法：

view.addBorder(toSide: .bottom, withColor: UIColor.lightGray.cgColor, andThickness: 0.2)

【讨论】：