An easy way to draw a circle using CAShapeLayer

An easy way to draw a circle is to create a CAShapeLayer and add a UIBezierPath.

objective-c

CAShapeLayer *circleLayer = [CAShapeLayer layer];[circleLayer setPath:[[UIBezierPath bezierPathWithOvalInRect:CGRectMake(50, 50, 100, 100)] CGPath]];

swift

let circleLayer = CAShapeLayer();circleLayer.path = UIBezierPath(ovalIn: CGRect(x: 50, y: 50, width: 100, height: 100)).cgPath;

After creating the CAShapeLayer we set its path to be a UIBezierPath.

Our UIBezierPath then draws a bezierPathWithOvalInRect. The CGRect we set will effect its size and position.

Now that we have our circle, we can add it to our UIView as a sublayer.

objective-c

[[self.view layer] addSublayer:circleLayer];

swift

view.layer.addSublayer(circleLayer)

Our circle is now visible in our UIView.

If we wish to customise our circle's color properties we can easily do so by setting the CAShapeLayer's stroke- and fill color.

objective-c

[circleLayer setStrokeColor:[[UIColor redColor] CGColor]];[circleLayer setFillColor:[[UIColor clearColor] CGColor]];

swift

shapeLayer.strokeColor = UIColor.red.cgColor;shapeLayer.fillColor = UIColor.clear.cgColor;

Additionall properties can be found over at 's documentation on the subject https://developer.apple.com/.../CAShapeLayer_class/index.html.

Using CAShapeLayer Class makes drawing easy...1.Create CAShapeLayer Object2.Create a Circular path 3.Set the path to the wanted CAShapeLayer path4.Add the layer to your view

  let shapeLayer = CAShapeLayer()  let center = view.center  let circulPath = UIBezierPath(arcCenter: center, radius: 100, startAngle: 0, endAngle: 2.0 * CGFloat.pi, clockwise: true)  shapeLayer.path = circulPath.cgPath   view.layer.addSublayer(shapeLayer)

Note That ,here I draw the circle from center of the view. You can also set the fill color for your circle like bellow:

  shapeLayer.fillColor = UIColor.red.cgColor

for further study you can check on CALayer.com