Set Background Gradient on Button in Swift

Question

I have no idea how to set the background gradient on a button (without making the background gradient an image). This is so different from Android.

Here\'s a class I

Answer 1

@Zeb answer is great but just to clean it up and make it a little more swifty. Computed read-only properties should avoid using get and returning Void is redundant:

typealias GradientPoints = (startPoint: CGPoint, endPoint: CGPoint)

enum GradientOrientation {
  case topRightBottomLeft
  case topLeftBottomRight
  case horizontal
  case vertical

var startPoint: CGPoint {
    return points.startPoint
}

var endPoint: CGPoint {
    return points.endPoint
}

var points: GradientPoints {
    switch self {
    case .topRightBottomLeft:
        return (CGPoint(x: 0.0, y: 1.0), CGPoint(x: 1.0, y: 0.0))
    case .topLeftBottomRight:
        return (CGPoint(x: 0.0, y: 0.0), CGPoint(x: 1, y: 1))
    case .horizontal:
        return (CGPoint(x: 0.0, y: 0.5), CGPoint(x: 1.0, y: 0.5))
    case .vertical:
        return (CGPoint(x: 0.0, y: 0.0), CGPoint(x: 0.0, y: 1.0))
    }
  }
}

extension UIView {

func applyGradient(withColours colours: [UIColor], locations: [NSNumber]? = nil) {
    let gradient: CAGradientLayer = CAGradientLayer()
    gradient.frame = self.bounds
    gradient.colors = colours.map { $0.cgColor }
    gradient.locations = locations
    self.layer.insertSublayer(gradient, at: 0)
}

func applyGradient(withColours colours: [UIColor], gradientOrientation orientation: GradientOrientation) {
    let gradient: CAGradientLayer = CAGradientLayer()
    gradient.frame = self.bounds
    gradient.colors = colours.map { $0.cgColor }
    gradient.startPoint = orientation.startPoint
    gradient.endPoint = orientation.endPoint
    self.layer.insertSublayer(gradient, at: 0)
  }
}

Answer 2

Here below you can find the solution for Swift3 (and Swift4 too) and a little bit extended (orientation helper):

typealias GradientPoints = (startPoint: CGPoint, endPoint: CGPoint)

enum GradientOrientation {
    case topRightBottomLeft
    case topLeftBottomRight
    case horizontal
    case vertical

    var startPoint : CGPoint {
        return points.startPoint
    }

    var endPoint : CGPoint {
        return points.endPoint
    }

    var points : GradientPoints {
        switch self {
        case .topRightBottomLeft:
            return (CGPoint(x: 0.0,y: 1.0), CGPoint(x: 1.0,y: 0.0))
        case .topLeftBottomRight:
            return (CGPoint(x: 0.0,y: 0.0), CGPoint(x: 1,y: 1))
        case .horizontal:
            return (CGPoint(x: 0.0,y: 0.5), CGPoint(x: 1.0,y: 0.5))
        case .vertical:
            return (CGPoint(x: 0.0,y: 0.0), CGPoint(x: 0.0,y: 1.0))
        }
    }
}

extension UIView {

    func applyGradient(with colours: [UIColor], locations: [NSNumber]? = nil) {
        let gradient = CAGradientLayer()
        gradient.frame = self.bounds
        gradient.colors = colours.map { $0.cgColor }
        gradient.locations = locations
        self.layer.insertSublayer(gradient, at: 0)
    }

    func applyGradient(with colours: [UIColor], gradient orientation: GradientOrientation) {
        let gradient = CAGradientLayer()
        gradient.frame = self.bounds
        gradient.colors = colours.map { $0.cgColor }
        gradient.startPoint = orientation.startPoint
        gradient.endPoint = orientation.endPoint
        self.layer.insertSublayer(gradient, at: 0)
    }
}

Answer 3

Here, I have taken one UIView and add button in it.

     @IBOutlet weak var btnCenter: UIButton!
     @IBOutlet weak var viewCenter: UIView!

    // Create a gradient layer
    let gradient = CAGradientLayer()

    // gradient colors in order which they will visually appear
    gradient.colors = [UIColor.yello.cgColor, UIColor.blue.cgColor]

    // Gradient from left to right
    gradient.startPoint = CGPoint(x: 0.0, y: 0.5)
    gradient.endPoint = CGPoint(x: 1.0, y: 0.5)

    // set the gradient layer to the same size as the view
    gradient.frame = viewCenter.bounds

    // add the gradient layer to the views layer for rendering
    viewCenter.layer.insertSublayer(gradient, at: 0)

    // Tha magic! Set the button as the views mask
    viewCenter.mask = btnCenter

    //Set corner Radius and border Width of button
    btnCenter.layer.cornerRadius =  btnCenter.frame.size.height / 2
    btnCenter.layer.borderWidth = 5.0

Answer 4

For Swift 2.0 to give gradients color to UIButton

let gradient: CAGradientLayer = CAGradientLayer()

gradient.colors = [(UIColor(red: 59.0/255.0, green: 187.0/255.0, blue: 182.0/255.0, alpha: 1.00).CGColor), (UIColor(red: 57.0/255.0, green: 174.0/255.0, blue: 236.0/255.0, alpha: 1.00).CGColor)]
gradient.locations = [0.0 , 1.0]

gradient.startPoint = CGPoint(x: 0.0, y: 1.0)
gradient.endPoint = CGPoint(x: 1.0, y: 1.0)
gradient.frame = CGRect(x: 0.0, y: 0.0, width: btn.frame.size.width, height: btn.frame.size.height)
btn.layer.insertSublayer(gradient, atIndex: 0)

Answer 5

There are already many answers there I want add what I did to achieve this. I use this custom Button GradientButton

import Foundation
import UIKit

class GradientButton: UIButton {

    let gradientColors : [UIColor]
    let startPoint : CGPoint
    let endPoint : CGPoint

    required init(gradientColors: [UIColor] = [UIColor.red, UIColor.blue],
                  startPoint: CGPoint = CGPoint(x: 0, y: 0.5),
                  endPoint: CGPoint = CGPoint(x: 1, y: 0.5)) {
        self.gradientColors = gradientColors
        self.startPoint = startPoint
        self.endPoint = endPoint

        super.init(frame: .zero)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func layoutSubviews() {
        super.layoutSubviews()

        let halfOfButtonHeight = layer.frame.height / 2
        contentEdgeInsets = UIEdgeInsets(top: 10, left: halfOfButtonHeight, bottom: 10, right: halfOfButtonHeight)

        layer.anchorPoint = CGPoint(x: 0.5, y: 0.5)

        backgroundColor = UIColor.clear

        // setup gradient

        let gradient = CAGradientLayer()
        gradient.frame = bounds
        gradient.colors = gradientColors.map { $0.cgColor }
        gradient.startPoint = startPoint
        gradient.endPoint = endPoint
        gradient.cornerRadius = 4

        // replace gradient as needed
        if let oldGradient = layer.sublayers?[0] as? CAGradientLayer {
            layer.replaceSublayer(oldGradient, with: gradient)
        } else {
            layer.insertSublayer(gradient, below: nil)
        }

        // setup shadow

        layer.shadowColor = UIColor.darkGray.cgColor
        layer.shadowPath = UIBezierPath(roundedRect: bounds, cornerRadius: halfOfButtonHeight).cgPath
        layer.shadowOffset = CGSize(width: 0.0, height: 1.0)
        layer.shadowOpacity = 0.85
        layer.shadowRadius = 4.0
    }

    override var isHighlighted: Bool {
        didSet {
            let newOpacity : Float = isHighlighted ? 0.6 : 0.85
            let newRadius : CGFloat = isHighlighted ? 6.0 : 4.0

            let shadowOpacityAnimation = CABasicAnimation()
            shadowOpacityAnimation.keyPath = "shadowOpacity"
            shadowOpacityAnimation.fromValue = layer.shadowOpacity
            shadowOpacityAnimation.toValue = newOpacity
            shadowOpacityAnimation.duration = 0.1

            let shadowRadiusAnimation = CABasicAnimation()
            shadowRadiusAnimation.keyPath = "shadowRadius"
            shadowRadiusAnimation.fromValue = layer.shadowRadius
            shadowRadiusAnimation.toValue = newRadius
            shadowRadiusAnimation.duration = 0.1

            layer.add(shadowOpacityAnimation, forKey: "shadowOpacity")
            layer.add(shadowRadiusAnimation, forKey: "shadowRadius")

            layer.shadowOpacity = newOpacity
            layer.shadowRadius = newRadius

            let xScale : CGFloat = isHighlighted ? 1.025 : 1.0
            let yScale : CGFloat = isHighlighted ? 1.05 : 1.0
            UIView.animate(withDuration: 0.1) {
                let transformation = CGAffineTransform(scaleX: xScale, y: yScale)
                self.transform = transformation
            }
        }
    }
}

You can make GradientButton instance like this.

let button = GradientButton.init(gradientColors:[UIColor.black, UIColor.white], startPoint: CGPoint(x: 0, y: 0), endPoint: CGPoint(x: 0, y: 1))

Answer 6

   class ButtonGradient : UIButton {
        override func layoutSubviews() {

            let layer : CAGradientLayer = CAGradientLayer()
            layer.frame.size = self.frame.size
            layer.frame.origin = CGPoint(x: 0, y: 0)

            //   layer.cornerRadius = CGFloat(frame.width / 20)
            let color0 = UIColor(red:255/255, green:122/255, blue:0/255, alpha:1.0).cgColor
            let color1 = UIColor(red:255/255, green:176/255, blue: 0/255, alpha:1.0).cgColor
            let color2 = UIColor(red:250/255, green:98/255, blue: 44/255, alpha:1.0).cgColor
            layer.locations = [0.5, 1.0]
            layer.startPoint = CGPoint(x: 0.0, y: 0.5)
            layer.endPoint = CGPoint(x: 0.5, y: 0.5)
            layer.colors = [color2,color0,color1]

            self.layer.insertSublayer(layer, at: 0)
        }
    }

After that directly assign "ButtonGredient" class to particular button in Storyboard.