围绕textview或标签快速绘制边框
问题描述:
myLabel.layer.borderWidth = 0.5
myLabel.layer.borderColor = UIColor.green.cgColor
这就是绘制边框的简单答案。然而,问题是我需要仅将边界绘制到右侧和底部。我还需要另一个标签来在右上角绘制边框。我怎样才能把边界画到特定的边,而不是全部四边?围绕textview或标签快速绘制边框
答
添加形状图层,绘制该层中的线。请注意,图层不参与自动布局,因此您需要将代码放入viewDidLayoutSubviews或子类uilabel中,然后在布局子视图中执行此操作。下面是使用的UILabel子类的游乐场例如:
import PlaygroundSupport
import UIKit
class L: UILabel {
var strokeColor = UIColor.blue
var strokeWidth = CGFloat(0.5)
private lazy var labelBorderLayer:CAShapeLayer = {
let shapeLayer = CAShapeLayer()
self.layer.addSublayer(shapeLayer)
return shapeLayer
}()
override func layoutSubviews() {
super.layoutSubviews()
let path = CGMutablePath()
path.move(to: CGPoint(x: 0, y: bounds.size.height))
path.addLine(to: CGPoint(x: bounds.size.width, y: bounds.size.height))
path.addLine(to: CGPoint(x: bounds.size.width, y: 0))
labelBorderLayer.path = path
labelBorderLayer.strokeColor = strokeColor.cgColor
labelBorderLayer.lineWidth = strokeWidth
labelBorderLayer.fillColor = UIColor.clear.cgColor
}
}
let v = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
let l = L(frame: v.frame.insetBy(dx: 50, dy: 80))
v.addSubview(l)
l.textColor = .white
l.textAlignment = .center
l.text = "gjgkjgjgjgj"
v.backgroundColor = .red
PlaygroundPage.current.liveView = v
答
我不知道你是否可以用实际的标签边框做到这一点。但是,你可以做类似于这个
public enum UIButtonBorderSide {
case Top, Bottom, Left, Right
}
extension UIButton {
public func addBorder(side: UIButtonBorderSide, color: UIColor, width: CGFloat) {
let border = CALayer()
border.backgroundColor = color.CGColor
switch side {
case .Top:
border.frame = CGRect(x: 0, y: 0, width: frame.size.width, height: width)
case .Bottom:
border.frame = CGRect(x: 0, y: self.frame.size.height - width, width: self.frame.size.width, height: width)
case .Left:
border.frame = CGRect(x: 0, y: 0, width: width, height: self.frame.size.height)
case .Right:
border.frame = CGRect(x: self.frame.size.width - width, y: 0, width: width, height: self.frame.size.height)
}
self.layer.addSublayer(border)
}
}
这就是UIButton,但你可以很容易地适应它。
来源:https://gist.github.com/Isuru-Nanayakkara/496d5713e61125bddcf5
希望这有助于
的可能的复制[CALayer的:添加边框仅在一侧(http://*.com/questions/7022656/calayer-add-a-border -only-AT-一侧) –