UIButton bottom shadow

I have a UIButton which is very similar to the standard iOS keyboard alphabet button.

I am not sure how to create a shadow only for the bottom layer like how iOS have done.

I use the below code, but I see a shadow on all the side, not just the bottom:

CALayer *buttonLayer = [[CALayer alloc] init];
buttonLayer.shadowColor = [UIColor grayColor].CGColor;
buttonLayer.shadowOffset = CGSizeMake(0.f,1.f);
buttonLayer.masksToBounds = NO;
buttonLayer.shadowOpacity = 1.f;

Can you please tell me how to achieve the same effect. Thanks in advance.

You can mix the cornerRadius and shadow properties. I tested it on iOS 8.

Objective-C:

[self.globeButton setImage:[UIImage imageNamed:@"Globe"] forState:UIControlStateNormal];
self.globeButton.backgroundColor = [UIColor colorWithRed:171 green:178 blue:186 alpha:1.0f];
// Shadow and Radius
self.globeButton.layer.shadowColor = [[UIColor colorWithRed:0 green:0 blue:0 alpha:0.25f] CGColor];
self.globeButton.layer.shadowOffset = CGSizeMake(0, 2.0f);
self.globeButton.layer.shadowOpacity = 1.0f;
self.globeButton.layer.shadowRadius = 0.0f;
self.globeButton.layer.masksToBounds = NO;
self.globeButton.layer.cornerRadius = 4.0f;

Swift:

globeButton.setImage(UIImage(named: "Globe"), for: .normal)
globeButton.backgroundColor = UIColor(red: 171/255, green: 178/255, blue: 186/255, alpha: 1.0)
// Shadow Color and Radius
globeButton.layer.shadowColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.25).cgColor
globeButton.layer.shadowOffset = CGSize(width: 0.0, height: 2.0)
globeButton.layer.shadowOpacity = 1.0
globeButton.layer.shadowRadius = 0.0
globeButton.layer.masksToBounds = false
globeButton.layer.cornerRadius = 4.0

Result:

SWIFT 3

import UIKit

class ButtonWithShadow: UIButton {

    override func draw(_ rect: CGRect) {
        updateLayerProperties()
    }

    func updateLayerProperties() {
        self.layer.shadowColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.25).cgColor
        self.layer.shadowOffset = CGSize(width: 0, height: 3)
        self.layer.shadowOpacity = 1.0
        self.layer.shadowRadius = 10.0
        self.layer.masksToBounds = false
    }

}

!! Only if you do not need corner radius and shadow simultaneously. Otherwise watch this.

Be sure to also set shadowRadius to 0:

Given a UIButton property named button set its backing layer properties like this:

self.button.layer.shadowColor = [UIColor grayColor].CGColor;
self.button.layer.shadowOffset = CGSizeMake(0, 1.0);
self.button.layer.shadowOpacity = 1.0;
self.button.layer.shadowRadius = 0.0;

I have created IBInspectable extension that will help you.

You can directly assign from storyboard

Swift 5

//MARK:- IBInspectable
extension UIView {
    @IBInspectable var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
            layer.masksToBounds = newValue > 0
        }
    }
    
    @IBInspectable var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }
    
    @IBInspectable var borderColor: UIColor? {
        get {
            return UIColor(cgColor: layer.borderColor!)
        }
        set {
            layer.borderColor = newValue?.cgColor
        }
    }
    
    @IBInspectable
    var shadowRadius: CGFloat {
        get {
            return layer.shadowRadius
        }
        set {
            layer.masksToBounds = false
            layer.shadowRadius = newValue
        }
    }
    
    @IBInspectable
    var shadowOpacity: Float {
        get {
            return layer.shadowOpacity
        }
        set {
            layer.masksToBounds = false
            layer.shadowOpacity = newValue
        }
    }
    
    @IBInspectable
    var shadowOffset: CGSize {
        get {
            return layer.shadowOffset
        }
        set {
            layer.masksToBounds = false
            layer.shadowOffset = newValue
        }
    }
    
    @IBInspectable
    var shadowColor: UIColor? {
        get {
            if let color = layer.shadowColor {
                return UIColor(cgColor: color)
            }
            return nil
        }
        set {
            if let color = newValue {
                layer.shadowColor = color.cgColor
            } else {
                layer.shadowColor = nil
            }
        }
    }
}

You can try with this code: (sorry, i only know swift, not obj c. this code will add bottom shadow on your button.

button.layer.masksToBounds = false
button.layer.shadowColor = UIColor(rgb: 0x000000, alpha: 1.0).CGColor
button.layer.shadowOpacity = 1.0
button.layer.shadowRadius = 0
button.layer.shadowOffset = CGSizeMake(0, 1.0)

View bottom shadow swift 4.2

viewTop.layer.shadowOffset = CGSize(width: 0, height: 1)
viewTop.layer.shadowColor = UIColor.lightGray.cgColor
viewTop.layer.shadowOpacity = 1
viewTop.layer.shadowRadius = 5
viewTop.layer.masksToBounds = false

in swift 2.0 add shadow uiview (uibutton) with code before class declaration or in swift file functions:

extension UIView {

    func addShadowView(width:CGFloat=0.2, height:CGFloat=0.2, Opacidade:Float=0.7, maskToBounds:Bool=false, radius:CGFloat=0.5){
         self.layer.shadowColor = UIColor.blackColor().CGColor
         self.layer.shadowOffset = CGSize(width: width, height: height)
         self.layer.shadowRadius = radius
         self.layer.shadowOpacity = Opacidade
         self.layer.masksToBounds = maskToBounds
    }

}

in viewdidload add this code

button.addShadowView()

CornerRadius and shadow don't mix well on the same layer. So you will have to embed your "to be cornered" UIButton inside an UIView. The shadow will be applied on this UIView.

The following code, given as an example, produces the image below it:

import UIKit

class CustomButton: UIButton {

    required init(coder decoder: NSCoder) {
        super.init(coder: decoder)

        backgroundColor = UIColor.whiteColor()
    }

    override func drawRect(rect: CGRect) {
        updateLayerProperties()
    }

    func updateLayerProperties() {
        layer.masksToBounds = true
        layer.cornerRadius = 12.0

        //superview is your optional embedding UIView
        if let superview = superview {
            superview.backgroundColor = UIColor.clearColor()
            superview.layer.shadowColor = UIColor.darkGrayColor().CGColor
            superview.layer.shadowPath = UIBezierPath(roundedRect: bounds, cornerRadius: 12.0).CGPath
            superview.layer.shadowOffset = CGSize(width: 2.0, height: 2.0)
            superview.layer.shadowOpacity = 1.0
            superview.layer.shadowRadius = 2
            superview.layer.masksToBounds = true
            superview.clipsToBounds = false
        }
    }

}

Put this method into your UIView extension and play with offset value

func drawShadow(shadowColor: UIColor = UIColor.black, opacity: Float =
0.3, offset: CGSize, radius: CGFloat = 5, shouldRasterize : Bool = false) {
        self.layer.shadowColor = shadowColor.cgColor
        self.layer.shadowOpacity = opacity
        self.layer.shadowOffset = offset
        self.layer.shadowRadius = radius
        self.layer.shouldRasterize = shouldRasterize
    }

To add shadow to a button with corner radius:

final class CustomButton: UIButton {

    private var shadowLayer: CAShapeLayer!

    override func layoutSubviews() {
        super.layoutSubviews()

        if shadowLayer == nil {
            shadowLayer = CAShapeLayer()
            shadowLayer.path = UIBezierPath(roundedRect: bounds, cornerRadius: 33).cgPath
            if self.backgroundColor != nil {
                shadowLayer.fillColor = self.backgroundColor?.cgColor
            }
            else{
                shadowLayer.fillColor = UIColor.white.cgColor
            }
            shadowLayer.shadowColor = UIColor.gray.cgColor
            shadowLayer.shadowPath = shadowLayer.path
            shadowLayer.shadowOffset = CGSize(width: 0.0, height: 3.0)
            shadowLayer.shadowOpacity = 0.4
            shadowLayer.shadowRadius = 2

            layer.insertSublayer(shadowLayer, at: 0)
            
        }

    }

}

You can try with this code:

    LoveButtonOutlet.layer.backgroundColor = UIColor.white.cgColor
    LoveButtonOutlet.layer.cornerRadius = 10
    LoveButtonOutlet.layer.borderWidth = 2
    LoveButtonOutlet.layer.borderColor = UIColor.black.cgColor
    LoveButtonOutlet.layer.shadowOffset = CGSize(width: 0, height: 1)
    LoveButtonOutlet.layer.shadowColor = UIColor.darkGray.cgColor
    LoveButtonOutlet.layer.shadowOpacity = 1
    LoveButtonOutlet.layer.shadowRadius = 5
    LoveButtonOutlet.layer.masksToBounds = false

extension UIButton
{
    func setButtonCornerRadiusOnly(getValue:CGFloat)
    {
        self.layer.cornerRadius = getValue
        self.clipsToBounds = true
    }
    
    func setButtonBorderColorAndHeight(getHeight:CGFloat,getColor:UIColor)
    {
        self.layer.borderColor = getColor.cgColor
        self.layer.borderWidth = getHeight
    }
    
    func setBtnWithShadow()
    {
        self.layer.shadowOffset = CGSize(width: 0.5, height: 0.4)
        self.layer.shadowOpacity = 0.5
        self.layer.shadowRadius = 1.5
        self.layer.cornerRadius = self.frame.size.height/2
        self.layer.masksToBounds =  false
    }
}