Swift - Problems with corner radius and drop shadow

Question

I\'m trying to create a button with rounded corners and a drop shadow. No matter how I switch up, the button will not display correctly. I\

Answer 1

Using CAShapeLayer and UIBezierPath we can easily add shadow and corner radius to UIView and the class derived from it like UIButton, UIImageView, UILabel etc.

We will add UIView Extension and the good point of this is, you only need to write just one line of code to achieve this.

You can round specific corner as well Just add below UIView Extension in your project:

 extension UIView {

  func addShadow(shadowColor: UIColor, offSet: CGSize, opacity: Float, shadowRadius: 
  CGFloat, cornerRadius: CGFloat, corners: UIRectCorner, fillColor: UIColor = .white) {

    let shadowLayer = CAShapeLayer()
    let size = CGSize(width: cornerRadius, height: cornerRadius)
    let cgPath = UIBezierPath(roundedRect: self.bounds, byRoundingCorners: corners, cornerRadii: size).cgPath //1
    shadowLayer.path = cgPath //2
    shadowLayer.fillColor = fillColor.cgColor //3
    shadowLayer.shadowColor = shadowColor.cgColor //4
    shadowLayer.shadowPath = cgPath
    shadowLayer.shadowOffset = offSet //5
    shadowLayer.shadowOpacity = opacity
    shadowLayer.shadowRadius = shadowRadius
    self.layer.addSublayer(shadowLayer)
  }
}

Now just write below code to add shadow and corner radius

  self.myView.addShadow(shadowColor: .black, offSet: CGSize(width: 2.6, height: 2.6), 
  opacity: 0.8, shadowRadius: 5.0, cornerRadius: 20.0, corners: [.topRight, .topLeft], 
  fillColor: .red)

Answer 2

If somebody need add shadows to rounded buttons in Swift 3.0, here is a good method to do it.

func addShadowForRoundedButton(view: UIView, button: UIButton, shadowColor: UIColor, shadowOffset: CGSize, opacity: Float = 1) {
    let shadowView = UIView()
    shadowView.backgroundColor = shadowColor
    shadowView.layer.opacity = opacity
    shadowView.layer.cornerRadius = button.bounds.size.width / 2
    shadowView.frame = CGRect(origin: CGPoint(x: button.frame.origin.x + shadowOffset.width, y: button.frame.origin.y + shadowOffset.height), size: CGSize(width: button.bouds.width, height: button.bounds.height))
    self.view.addSubview(shadowView)
    view.bringSubview(toFront: button)
}

Use this method in func viewDidLayoutSubviews() as bellow:

override func viewDidLayoutSubviews() {
    addShadowForRoundedButton(view: self.view, button: button, shadowColor: .black, shadowOffset: CGSize(width: 2, height: 2), opacity: 0.5)
}

The effect of this method is: