Shadow left and right of UIView - iphone

Question

Hi i like to add an CALayer Shadow to an View where the shadow was left and right of the view the simplest way was:
someView.layer.shadowColor = [[UIColor blackColor] CGColor];
someView.layer.shadowOffset = CGSizeMake(0.0f,0.0f);
someView.layer.shadowOpacity = 1.0f;
someView.layer.shadowRadius = 10.0f;
someView.layer.shadowPath = [[UIBezierPath bezierPathWithRect:someView.bounds] CGPath];
but i will add a bigger shadow as like a shadow when i increase the shadowRadius it do not look good. How i can make a shadow that looks good at left and right.

Answer 1

I think 10 is a pretty big shadow radius, try 3 or 4 instead, also opacity I usually use 0.7:
someView.layer.shadowColor = [[UIColor blackColor] CGColor];
someView.layer.shadowOffset = CGSizeMake(0.0f,0.0f);
someView.layer.shadowOpacity = 0.7f;
someView.layer.shadowRadius = 4.0f;
If you want the shadow only on left and right, then inset the rectangle on the top and bottom so the top and bottom shadow are hidden behind your view:
CGRect shadowRect = CGRectInset(someView.bounds, 0, 4); // inset top/bottom
someView.layer.shadowPath = [[UIBezierPath bezierPathWithRect:shadowRect] CGPath];
I'm not really sure if that's what you wanted.

Answer 2

swift 3.0 version
imageView.layer.shadowOpacity = 0.8
imageView.layer.shadowOffset = CGSize(width: 0, height: 3)
imageView.layer.shadowRadius = 4.0
let shadowRect: CGRect = imageView.bounds.insetBy(dx: 0, dy: 4)
imageView.layer.shadowPath = UIBezierPath(rect: shadowRect).cgPath

Answer 3

progrmr's answer was very helpful, cheers!
I made a slide-out menu and I had a problem with the shadow surrounding my VC and disrupting the navigation bar. Turned out I had to inset the shadow layer.
Here's my solution using swift:
rightViewController!.view.layer.shadowOpacity = 0.8
rightViewController!.view.layer.shadowOffset = CGSizeMake(0, 3)
rightViewController!.view.layer.shadowRadius = 4.0
let shadowRect: CGRect = CGRectInset(rightViewController!.view.bounds, 0, 4); // inset top/bottom
rightViewController!.view.layer.shadowPath = UIBezierPath(rect: shadowRect).CGPath

Answer 4

I created a shadow that can be used at the top/bottom or left/right, without prejudice at all. No shadow will appear in the left/right if you choose top/bottom, and so on. I hope I helped. Here's the code:
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let imgView = UIImageView(frame: CGRect(x: self.view.bounds.midX - 150, y: self.view.bounds.midY - 150, width: 300, height: 300))
imgView.contentMode = .scaleToFill
imgView.image = UIImage(named: "name image")
self.view.addSubview(imgView)
//You can put left/right or top/bottom
imgView.addShadow(sides: .leftRight, constant: 10, alpha: 5)
}
}
extension UIView{
func addShadow(sides: Sides, constant: Int, alpha: Int){
if(constant > 0 && alpha > 0){
switch sides {
case .leftRight:
let view = UIView(frame: CGRect(x: -CGFloat(constant), y: 0, width: self.bounds.width + CGFloat((constant * 2)), height: self.bounds.height))
self.addSubview(view)
addMask(sides: .leftRight, view: view, constant: constant, shadowRadius: alpha)
case .topBottom:
let view = UIView(frame: CGRect(x: 0, y: -CGFloat(constant), width: self.bounds.width , height: self.bounds.height + CGFloat(constant * 2)))
self.addSubview(view)
addMask(sides: .topBottom, view: view, constant: constant, shadowRadius: alpha)
}
}
}
private func addMask(sides:Sides, view: UIView, constant: Int, shadowRadius:Int){
let mutablePath = CGMutablePath()
let mask = CAShapeLayer()
switch sides {
case .leftRight:
mutablePath.addRect(CGRect(x: -CGFloat(constant), y: 0, width: view.bounds.width, height: view.bounds.height))
mutablePath.addRect(CGRect(x: CGFloat(constant) , y: 0, width: view.bounds.width , height: view.bounds.height))
case .topBottom:
mutablePath.addRect(CGRect(x: 0, y: -CGFloat(constant), width: view.bounds.width, height: view.bounds.height))
mutablePath.addRect(CGRect(x: 0, y: CGFloat(constant) , width: view.bounds.width , height: view.bounds.height))
}
mask.path = mutablePath
mask.fillRule = CAShapeLayerFillRule.evenOdd
mask.fillColor = UIColor(white:1.0, alpha: 0.2).cgColor
view.layer.mask = mask
view.layer.addSublayer(mask)
mask.shadowColor = UIColor.black.cgColor
mask.shadowRadius = CGFloat(shadowRadius)
mask.shadowOpacity = 1.0
mask.shadowOffset = CGSize(width: 0, height: 0)
}
}
enum Sides{
case leftRight
case topBottom
}
You just need to call the extension UIView, which has the addShadow() function and pass the parameters you want.