add UIBezierPath to UIView - ios

Question

i have a UIView with layout constraint (width:400, height:180) and i want to add a bezier inside the view.
my bezier is this:
UIBezierPath* bezierPath = [UIBezierPath bezierPath];
// origin, height | left border
[bezierPath moveToPoint: CGPointMake(0, 20)];
// origin, height | left border
[bezierPath addLineToPoint: CGPointMake(0, _donationView.frame.size.height)];
// height, width | bottom border
[bezierPath addLineToPoint: CGPointMake(_donationView.frame.size.width , _donationView.frame.size.height)];
[bezierPath addLineToPoint: CGPointMake(_donationView.frame.size.width, 20)];
[bezierPath addLineToPoint: CGPointMake(_donationView.frame.size.width - 20, 20)];
[bezierPath addLineToPoint: CGPointMake(_donationView.frame.size.width - 30, 15)];
[bezierPath addLineToPoint: CGPointMake(_donationView.frame.size.width - 40, 20)];
[bezierPath addLineToPoint: CGPointMake(0, 20)];
[bezierPath closePath];
[UIColor.grayColor setFill];
[bezierPath fill];
[UIColor.blackColor setStroke];
bezierPath.lineWidth = 1;
[bezierPath stroke];
after creating bezier i pass to:
CAShapeLayer *shapeView = [[CAShapeLayer alloc] initWithLayer:_donationView.layer];
[shapeView setPath:bezierPath.CGPath];
_donationView.layer.mask = shapeView;
but the bezier goes to this CGRect(0, 0, 240, 128);
how can i have a CGRect of (0,0,400, 180)?
thanks guys

Answer 1

The problem is that you're doing this too soon, before donationView has attained its final size. Thus, when you read off its frame.size, you are getting the wrong result. You need to postpone the addition of the mask until after layout has taken place.
You can also run into further issues if donationView is ever resized later. It is quite annoying that a mask layer (or any layer) doesn't get to participate in autolayout. So if donationView is resized, you will have to remove this mask and create a new mask with the correct size and add it again.