CAShapeLayer with border and fill color and roundi

Question

How do I use CAShapeLayer to draw a line that has both a border color, border width and fill color?

Here's what I've tried, but it's only ever blue...

self.lineShape.strokeColor = [UIColor blueColor].CGColor;
self.lineShape.fillColor = [UIColor greenColor].CGColor;
self.lineShape.lineWidth = 100;
self.lineShape.lineCap = kCALineCapRound;
self.lineShape.lineJoin = kCALineJoinRound;
UIBezierPath* path = [UIBezierPath bezierPath];
[path moveToPoint:self.lineStart];
[path addLineToPoint:self.lineEnd];
self.lineShape.path = path.CGPath;

Answer 1

In Swift 3. an extension method of UIView.

// Usage:
self.btnGroup.roundCorner([.topRight, .bottomRight], radius: 4.0, borderColor: UIColor.red, borderWidth: 1.0)

// Apply round corner and border. An extension method of UIView.
public func roundCorner(_ corners: UIRectCorner, radius: CGFloat, borderColor: UIColor, borderWidth: CGFloat) {
    let path = UIBezierPath.init(roundedRect: self.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))

    let mask = CAShapeLayer()
    mask.path = path.cgPath
    self.layer.mask = mask

    let borderPath = UIBezierPath.init(roundedRect: self.bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
    let borderLayer = CAShapeLayer()
    borderLayer.path = borderPath.cgPath
    borderLayer.lineWidth = borderWidth
    borderLayer.strokeColor = borderColor.cgColor
    borderLayer.fillColor = UIColor.clear.cgColor
    borderLayer.frame = self.bounds
    self.layer.addSublayer(borderLayer)
}

Answer 2

    self.lineShapeBorder = [[CAShapeLayer alloc] init];
    self.lineShapeBorder.zPosition = 0.0f;
    self.lineShapeBorder.strokeColor = [UIColor blueColor].CGColor;
    self.lineShapeBorder.lineWidth = 25;
    self.lineShapeBorder.lineCap = kCALineCapRound;
    self.lineShapeBorder.lineJoin = kCALineJoinRound;

    self.lineShapeFill = [[CAShapeLayer alloc] init];
    [self.lineShapeBorder addSublayer:self.lineShapeFill];
    self.lineShapeFill.zPosition = 0.0f;
    self.lineShapeFill.strokeColor = [UIColor greenColor].CGColor;
    self.lineShapeFill.lineWidth = 20.0f;
    self.lineShapeFill.lineCap = kCALineCapRound;
    self.lineShapeFill.lineJoin = kCALineJoinRound;

// ...

    UIBezierPath* path = [UIBezierPath bezierPath];
    [path moveToPoint:self.lineStart];
    [path addLineToPoint:self.lineEnd];
    self.lineShapeBorder.path = self.lineShapeFill.path = path.CGPath;

Answer 3

If you set the layer's fillColor property to something other than nil or transparent, the layer will fill its path.

If you set the layer's lineWidth to a number larger than zero and you set its strokeColor to something other than nil or transparent, the layer will stroke its path.

If you set all of those properties, the layer will fill and stroke its path. It draws the stroke after the fill.

The layer's path must actually enclose some area in order for it to fill anything. In your post, you set the path like this:

UIBezierPath* path = [UIBezierPath bezierPath];
[path moveToPoint:self.lineStart];
[path addLineToPoint:self.lineEnd];
self.lineShape.path = path.CGPath;

That path contains a single line segment. It doesn't enclose any area, so the layer has nothing to fill.