iOS：以编程方式在UIView中绘制线条

Question

我试图创建图片中建模的UIView。虽然，我的代码似乎有问题。知道为什么吗？

在评论的帮助下解决了！正确的代码已更新！

更新：我创建了一个自定义UIView类这是基于注释的新代码。

从这里获取drawLine：使用UIBezierPath绘制一条线

Answer 1

实现以上图像的代码：

//Post this function in your TableViewController
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
    let view = HeaderTableView()
    view.title.text = "THIS WEEK"

    return view
}

//Custom UIView Class
class CustomView: UIView {

var shouldSetupConstraints = true
var title: UILabel!
// Only override draw() if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func draw(_ rect: CGRect) {
    let textStartX = Int((title.frame.minX))
    let textEndX = Int((title.frame.maxX))
    let midY = Int(self.frame.midY)
    self.drawLine(startX: 8, toEndingX: textStartX - 8, startingY: midY, toEndingY: midY, ofColor: UIColor.white, widthOfLine: 1, inView: self)
    self.drawLine(startX: textEndX + 8, toEndingX: Int(self.frame.maxX) - 8, startingY: midY, toEndingY: midY, ofColor: UIColor.white, widthOfLine: 1, inView: self)

}



override init(frame: CGRect) {
    super.init(frame: frame)
    title = UILabel()
    self.addSubview(title)

    title.textAlignment = .center
    title.textColor = UIColor.white
    title.translatesAutoresizingMaskIntoConstraints = false

}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

override func updateConstraints() {
    if(shouldSetupConstraints) {
        // AutoLayout constraints
        let xConstraint = NSLayoutConstraint(item: title, attribute: .centerX, relatedBy: .equal, toItem: self, attribute: .centerX, multiplier: 1, constant: 0)
        let yConstraint = NSLayoutConstraint(item: title, attribute: .centerY, relatedBy: .equal, toItem: self, attribute: .centerY, multiplier: 1, constant: 0)
        self.addConstraints([xConstraint, yConstraint])
        shouldSetupConstraints = false
    }
    super.updateConstraints()
}

func drawLine(startX: Int, toEndingX endX: Int, startingY startY: Int, toEndingY endY: Int, ofColor lineColor: UIColor, widthOfLine lineWidth: CGFloat, inView view: UIView) {

    let path = UIBezierPath()
    path.move(to: CGPoint(x: startX, y: startY))
    path.addLine(to: CGPoint(x: endX, y: endY))

    let shapeLayer = CAShapeLayer()
    shapeLayer.path = path.cgPath
    shapeLayer.strokeColor = lineColor.cgColor
    shapeLayer.lineWidth = lineWidth

    view.layer.addSublayer(shapeLayer)

}
}

学分：

• 用UIBezierPath画一条线

• https://medium.com/write-code/creating-uiviews-programmatically-in-swift-55f5d14502ae