How to add shadow to border?

Stack Overflow Question

Link: https://stackoverflow.com/questions/79939205/how-to-add-shadow-to-border

Published: 2026-05-11T07:29:30Z

Updated: 2026-05-11T08:02:46Z

Author: steveSarsawa

Tags: ios, swift, uibutton

Summary:

        <p>I'm trying to add shadow to Border, but it is not working. Shadow should as seen in image, but actual requirement is like Button will be clear background, and shadow around border. So how can I achieve it?</p>

  private let borderGlowLayer = CAShapeLayer()  
    
  override init(frame: CGRect) {  
      super.init(frame: frame)  
      setup()  
  }  
    
  required init?(coder: NSCoder) {  
      super.init(coder: coder)  
      setup()  
  }  
    
  private func setup() {  
      backgroundColor = .clear  
      layer.masksToBounds = false  
      clipsToBounds = false  
        
      borderGlowLayer.fillColor   = UIColor.clear.cgColor  
      borderGlowLayer.strokeColor = UIColor.clear.cgColor  
      borderGlowLayer.lineWidth   = 2.5  
      borderGlowLayer.shadowOffset  = .zero  
      borderGlowLayer.shadowRadius  = 0  
      borderGlowLayer.shadowOpacity = 0  
      borderGlowLayer.masksToBounds = false  
      layer.addSublayer(borderGlowLayer)  
  }  
    
  override func layoutSubviews() {  
      super.layoutSubviews()  
      layer.masksToBounds = false  
      clipsToBounds = false  
      borderGlowLayer.frame = bounds  
      borderGlowLayer.path  = UIBezierPath(roundedRect: bounds, cornerRadius: 20).cgPath  
  }  
    
  override func didUpdateFocus(in context: UIFocusUpdateContext, with coordinator: UIFocusAnimationCoordinator) {  
      super.didUpdateFocus(in: context, with: coordinator)  
      coordinator.addCoordinatedAnimations {  
          if self.isFocused {  
              self.borderGlowLayer.strokeColor  = Colors.focused_border.cgColor  
              self.borderGlowLayer.shadowColor  = Colors.focused_border.cgColor  
              self.borderGlowLayer.shadowRadius  = 12  
              self.borderGlowLayer.shadowOpacity = 1.0  
          } else {  
              self.borderGlowLayer.strokeColor   = UIColor.clear.cgColor  
              self.borderGlowLayer.shadowOpacity = 0.0  
              self.borderGlowLayer.shadowRadius  = 0  
          }  
      }  
  }  

}