How to create rounded corners with CAShapeLayer

Question

Is there a way to add rounded corners to a CAShapeLayer? In my case I needed the shape layer to create a dashed border via lineDashPattern.

^ notice how the dashed line is not rounded

Answer 1

The answer is simple. Create a bézier path with rounded corners.

UPDATE for Swift

view.clipsToBounds = true 
view.layer.cornerRadius = 10.0
let border = CAShapeLayer()
border.path = UIBezierPath(roundedRect:view.bounds, cornerRadius:10.0).cgPath
border.frame = view.bounds
border.fillColor = nil 
border.strokeColor = UIColor.purple.cgColor
border.lineWidth = borderWidth * 2.0 // doubled since half will be clipped
border.lineDashPattern = [15.0]
view.layer.addSublayer(border)

Objective-C

// (This old code assumes this is within a view with a custom property "border".)
self.clipsToBounds = YES; 
self.layer.cornerRadius = 10.0;

self.border = [CAShapeLayer layer];
self.border.fillColor = nil;
self.border.path = [UIBezierPath bezierPathWithRoundedRect:self.bounds cornerRadius:10.0].cgPath;
self.border.frame = self.bounds;
    
self.border.strokeColor = [UIColor purpleColor].CGColor;
self.border.lineWidth = borderWidth * 2; // double desired width as half will be clipped
self.border.lineDashPattern = @[@15];

[self.layer addSublayer:self.border];