用 UIBezierPath 画一条线

Question

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

有没有更好的方法来做到这一点？

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()
}

Answer 1

最终这样做了：

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)
}

Answer 2

Swift 3.1 版本的 William Falcon's Answer + 改进

这只是已经接受的答案的更新版本，我只是添加了一点。

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，实施将是

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

我从接受的答案中改变了什么

我将 vars 更改为 let，并且更容易输入 x 和 y 的开始和结束。 我还允许用户更改线条的宽度。

我选择了 Int 类型的值，但您可以将它们更改为其他允许的选项。

Answer 3

斯威夫特 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)
}

Answer 4

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)

在底部绘制水平线：

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)