Draw a line with UIBezierPath - ios

Question

First time using BezierPaths, wondering how this function is actually supposed to be implemented. Currently the bezier path moves within the frame of the image, as opposed to drawing on screen.
Is there a better way to do it?
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

Ended up doing it this way:
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 Version of William Falcon's Answer + Improved
This is just an updated version of already accepted answer, and I just added a little bit more to it.
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)
}
And of course the implementation would be
drawLineFromPointToPoint(startX: Int, toEndingX: Int, startingY: Int, toEndingY: Int, ofColor: UIColor, widthOfLine: CGFloat, inView: UIView)
What I changed from accepted answer
I changed the vars to lets, and made it easier to input the start and end of both the x and the y. I also allow the user to change the width of the line.
I chose for the values to be of type Int, but you can change those to be the other allowed options.

Answer 3

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)
}

Answer 4

To draw horizontal line on top:
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)
To draw horizontal line on bottom:
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)