How to fill a bezier path with gradient color

Question

I have a UIBezierPath inside my custom UIView draw(_ rect: CGRect) function. I would like to fill the path with a gradient color. Please can anybody guide me how can I do that.

I need to fill the clip with a gradient color and then stroke the path with black color.

There are some posts in SO which does not solve the problem. For example Swift: Gradient along a bezier path (using CALayers) this post guides how to draw on a layer in UIView but not in a UIBezierPath.

NB: I am working on Swift-3

Answer 1

To answer this question of yours,

I have a UIBezierPath inside my custom UIView draw(_ rect: CGRect) function. I would like to fill the path with a gradient color.

Lets say you have an oval path,

let path = UIBezierPath(ovalIn: CGRect(x: 0, y: 0, width: 100, height: 100))

To create a gradient,

let gradient = CAGradientLayer()
gradient.frame = path.bounds
gradient.colors = [UIColor.magenta.cgColor, UIColor.cyan.cgColor]

We need a mask layer for gradient,

let shapeMask = CAShapeLayer()
shapeMask.path = path.cgPath

Now set this shapeLayer as mask of gradient layer and add it to view's layer as subLayer

gradient.mask = shapeMask
yourCustomView.layer.addSublayer(gradient)

Update Create a base layer with stroke and add before creating gradient layer.

let shape = CAShapeLayer()
shape.path = path.cgPath
shape.lineWidth = 2.0
shape.strokeColor = UIColor.black.cgColor
self.view.layer.addSublayer(shape)

let gradient = CAGradientLayer()
gradient.frame = path.bounds
gradient.colors = [UIColor.magenta.cgColor, UIColor.cyan.cgColor]

let shapeMask = CAShapeLayer()
shapeMask.path = path.cgPath
gradient.mask = shapeMask

self.view.layer.addSublayer(gradient)