title: BezierPath and masking
body: <p>I want to set up UIBezierPath as mask into my view:
  The goal is something like this:
  <img src="https://i.stack.imgur.com/cXaeD.png" alt="enter image description here"></p>
  
  <p>So i draw the View with frame:</p>
  
  <pre><code>CGFloat round = 80;
  UIView *myView = [[UIView alloc] initWithFrame:CGRectMake(self.frame.size.width/2-105, 0, 210, 60+round)];
  myView.backgroundColor = [UIColor redColor];
  </code></pre>
  
  <p>And then try to add BezierMask:</p>
  
  <pre><code>UIBezierPath *aPath = [UIBezierPath bezierPath];
  
  CGSize viewSize = CGSizeMake(myView.frame.size.width, myView.frame.size.height); //(210,80)
  CGPoint startPoint = CGPointMake(myView.frame.origin.x,myView.frame.origin.y); //(279,0)
  
  [aPath moveToPoint:startPoint]; //(279,0)
  
  [aPath addLineToPoint:CGPointMake(startPoint.x+viewSize.width,startPoint.y)]; //(489,0)
  [aPath addLineToPoint:CGPointMake(startPoint.x+viewSize.width,startPoint.y+viewSize.height-round)]; //(489,60)
  [aPath addQuadCurveToPoint:CGPointMake(startPoint.x,startPoint.y+viewSize.height-round) controlPoint:CGPointMake(startPoint.x+(viewSize.width/2),80)]; //(279,60) : (384,80)
  
  [aPath closePath];
  
  CAShapeLayer *layer = [CAShapeLayer layer];
  layer.frame = myView.bounds;
  layer.path = aPath.CGPath;
  myView.layer.mask = layer;
  
  [self addSubview:myView];
  </code></pre>
  
  <p>But my view is disappearing after that. Why?</p>