UIView shadow not visible - swift

Question

I have a UIView called containerView.
Upon creating the UIView & Adding it to the main view, I'm trying to add a little shadow. My code:
let containerView = UIView()
let bg_clear = UIColor(hexString: "#34495E")
containerView.backgroundColor = bg_clear
containerView.layer.cornerRadius = 15
containerView.clipsToBounds = false
containerView.dropShadow() // Generate Shadow
view.addSubview(containerView)
containerView.translatesAutoresizingMaskIntoConstraints = false
containerView.heightAnchor.constraint(equalToConstant: 50).isActive = true
containerView.widthAnchor.constraint(equalToConstant: 300).isActive = true
containerView.centerXAnchor.constraint(equalTo: tabBar.centerXAnchor).isActive = true
Code to generate the Shadow:
extension UIView {
func dropShadow(scale: Bool = true) {
layer.masksToBounds = false
layer.shadowColor = UIColor(hexString: "#000000").cgColor
layer.shadowOpacity = 0.5
layer.shadowOffset = CGSize(width: -1, height: 1)
layer.shadowRadius = 1
layer.shadowPath = UIBezierPath(rect: bounds).cgPath
layer.shouldRasterize = true
layer.rasterizationScale = scale ? UIScreen.main.scale : 1
}
}

Answer 1

This should help :
extension UIView {
func addShadow(withOpacity opacity:Float, radius:CGFloat, andColor color:UIColor) {
self.layer.shadowColor = color.cgColor
self.layer.shadowOffset = CGSize(width:-1.0, height:1.0)
self.layer.shadowOpacity = opacity
self.layer.shadowRadius = radius
}
}
Example :
containerView.addShadow(withOpacity: 0.4, radius: 0.4, andColor: .black)

Answer 2

A few points to note:
Make sure your container view is not too near the left or the bottom of the screen, because the shadow is going show up to the left and below the container view.
Make sure you use a rounded rect for the shadow path, because your container view has a non-zero corner radius.
If you still can't see the shadow, try increasing the shadow offset.
You can copy and paste this code into a playground and open the live view:
extension UIView {
func dropShadow(scale: Bool = true) {
layer.masksToBounds = false
layer.shadowColor = UIColor.black.cgColor
layer.shadowOpacity = 0.5
layer.shadowOffset = CGSize(width: -5, height: 5) // I made this larger
layer.shadowRadius = 1
// I used a rounded rect here
layer.shadowPath = UIBezierPath(roundedRect: self.bounds, cornerRadius: self.layer.cornerRadius).cgPath
layer.shouldRasterize = true
layer.rasterizationScale = scale ? UIScreen.main.scale : 1
}
}
let view = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
view.backgroundColor = .white
let containerView = UIView(frame: CGRect(x: 10, y: 10, width: 100, height: 100))
let bg_clear = UIColor.green
containerView.backgroundColor = bg_clear
containerView.layer.cornerRadius = 15
containerView.clipsToBounds = false
containerView.dropShadow() // Generate Shadow
view.addSubview(containerView)
PlaygroundPage.current.liveView = view
You should see: