Ios 用UIBezierPath画一条线

第一次使用BezierPath，想知道这个函数实际上应该如何实现。当前，贝塞尔路径在图像帧内移动，而不是在屏幕上绘制

有更好的方法吗

func drawLineFromPoint(start : CGPoint, toPoint end:CGPoint, ofColor lineColor: UIColor, inView view:UIView) {

    var maxWidth = abs(start.x - end.x)
    var maxHeight = abs(start.y - end.y)

    var contextSize : CGSize!
    if maxWidth == 0 {
        contextSize = CGSize(width: 1, height: maxHeight)
    }else {
        contextSize = CGSize(width: maxWidth, height: 1)
    }

    //design the path
    UIGraphicsBeginImageContextWithOptions(contextSize, false, 0)
    var path = UIBezierPath()
    path.lineWidth = 1.0
    lineColor.set()

    //draw the path and make visible
    path.moveToPoint(start)
    path.addLineToPoint(end)
    path.stroke()

    //create image from path and add to subview
    var image = UIGraphicsGetImageFromCurrentImageContext()
    var imageView = UIImageView(image: image)
    view.addSubview(imageView)
    UIGraphicsEndImageContext()
}

---

结果是这样做的：

func drawLineFromPoint(start : CGPoint, toPoint end:CGPoint, ofColor lineColor: UIColor, inView view:UIView) {
    
    //design the path
    let path = UIBezierPath()
    path.move(to: start)
    path.addLine(to: end)
    
    //design path in layer
    let shapeLayer = CAShapeLayer()
    shapeLayer.path = path.cgPath
    shapeLayer.strokeColor = lineColor.CGColor
    shapeLayer.lineWidth = 1.0
    
    view.layer.addSublayer(shapeLayer)
}

---

William Falcon答案的Swift 3.1版+改进版

这只是一个已经被接受的答案的更新版本，我只是添加了一点更多的内容

func drawLineFromPointToPoint(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)

}

当然，实施过程将是

drawLineFromPointToPoint(startX: Int, toEndingX: Int, startingY: Int, toEndingY: Int, ofColor: UIColor, widthOfLine: CGFloat, inView: UIView)

我对已接受答案的更改

我将变量更改为let，并使输入x和y的开始和结束变得更容易。我还允许用户更改线条的宽度

---

我选择了Int类型的值，但您可以将其更改为其他允许的选项。

要在顶部绘制水平线：

let path = UIBezierPath()
path.moveToPoint(CGPoint(x: 0, y: 0))
path.addLineToPoint(CGPoint(x: yourView.frame.width, y: 0))

let shapeLayer = CAShapeLayer()
shapeLayer.path = path.CGPath
shapeLayer.strokeColor = UIColor.lightGrayColor().CGColor
shapeLayer.lineWidth = 0.5

yourView.layer.addSublayer(shapeLayer)

---

要在底部绘制水平线，请执行以下操作：

let path = UIBezierPath()
path.moveToPoint(CGPoint(x: 0, y: yourView.frame.height))
path.addLineToPoint(CGPoint(x: yourView.frame.width, y: yourView.frame.height))

let shapeLayer = CAShapeLayer()
shapeLayer.path = path.CGPath
shapeLayer.strokeColor = UIColor.lightGrayColor().CGColor
shapeLayer.lineWidth = 0.5

yourView.layer.addSublayer(shapeLayer)

---

Swift 4

func drawLineFromPoint(start : CGPoint, toPoint end:CGPoint, ofColor lineColor: UIColor, inView view:UIView) {

    //design the path
    let path = UIBezierPath()
    path.move(to: start)
    path.addLine(to: end)

    //design path in layer
    let shapeLayer = CAShapeLayer()
    shapeLayer.path = path.cgPath
    shapeLayer.strokeColor = lineColor.cgColor
    shapeLayer.lineWidth = 1.0

    view.layer.addSublayer(shapeLayer)
}

---

另一种更直接的方法是使用

CAShapeLayer

或custom

drawRect

，而不是像这样使用图像，如下所述：我没有在layer中使用设计路径。但是只要

path.Stroke

。我不明白为什么没有增加这一行。有什么建议吗@威廉猎鹰