How to apply gradients to mulitple custom uiviews?

Question

I have 6 custom uiviews arranged. Also I have tried applying gradient using various techniques.

How to call the functions or how to apply gradient for mulitple views having different cgcolor codes.

        func onebg(){
                    applyGradient(color_1: UIColor(red: 218.0/255.0, green: 52.0/255.0, blue: 204.0/255.0, alpha: 1.0).cgColor, color_2: UIColor(red: 149.0/255.0, green: 39.0/255.0, blue: 137.0/255.0, alpha: 1.0).cgColor, view: calendarView)
                }

        func twobg(){
                    applyGradient(color_1: UIColor(red: 104.0/255.0, green: 220.0/255.0, blue: 108.0/255.0, alpha: 1.0).cgColor, color_2: UIColor(red: 28.0/255.0, green: 170.0/255.0, blue: 87.0/255.0, alpha: 1.0).cgColor, view: classroomView)
                }

        func threebg(){
                    applyGradient(color_1: UIColor(red: 0.0/255.0, green: 144.0/255.0, blue: 214.0/255.0, alpha: 1.0).cgColor, color_2: UIColor(red: 34.0/255.0, green: 66.0/255.0, blue: 138.0/255.0, alpha: 1.0).cgColor, view: appointmentView)
                }


        I have called this 6 methods like, onebg() twobg() from viewdidload(). But it is not applying and most importantly what i am getting is , the gradient color is applied only for last view. 

        func applyGradient(color_1 : CGColor , color_2: CGColor , view : UIView)  {

                    gradientLayer.frame = view.bounds

                    let color1 = color_1

                    let color2 = color_2

                    gradientLayer.colors = [color1, color2]

                    gradientLayer.locations = [0.0, 0.75, 0.25, 1.0]

                    view.layer.insertSublayer(gradientLayer, at: 0)
        }

This is the method im calling for applying ,by adding insertsublayer for gradients.Please help.

Answer 1

Swift 4.0

You need to implement this code in one file and assign to view, configure in inspector attribute your gradient as below image

You can try this way.

@IBDesignable class xGradientView: UIView {

    @IBInspectable
    var cornerRadius: CGFloat {
        get {
            return layer.cornerRadius
        }
        set {
            layer.cornerRadius = newValue
        }
    }

    @IBInspectable
    var borderWidth: CGFloat {
        get {
            return layer.borderWidth
        }
        set {
            layer.borderWidth = newValue
        }
    }

    @IBInspectable
    var borderColor: UIColor? {
        get {
            if let color = layer.borderColor {
                return UIColor(cgColor: color)
            }
            return nil
        }
        set {
            if let color = newValue {
                layer.borderColor = color.cgColor
            } else {
                layer.borderColor = nil
            }
        }
    }

    @IBInspectable
    var shadowRadius: CGFloat {
        get {
            return layer.shadowRadius
        }
        set {
            layer.shadowRadius = newValue
        }
    }
    @IBInspectable
    var shadowOpacity: Float {
        get {
            return layer.shadowOpacity
        }
        set {
            layer.shadowOpacity = newValue
        }
    }

    @IBInspectable
    var shadowOffset: CGSize {
        get {
            return layer.shadowOffset
        }
        set {
            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
            }
        }
    }

//    MARK:- Gradient Color

    @IBInspectable var startColor:   UIColor = .clear { didSet { updateColors() }}
    @IBInspectable var endColor:     UIColor = .clear { didSet { updateColors() }}
    @IBInspectable var startLocation: Double =   0.0 { didSet { updateLocations() }}
    @IBInspectable var endLocation:   Double =   0.0 { didSet { updateLocations() }}
    @IBInspectable var horizontalMode:  Bool =  false { didSet { updatePoints() }}
    @IBInspectable var diagonalMode:    Bool =  false { didSet { updatePoints() }}
    var gradientSet = [[CGColor]]()
    var currentGradient: Int = 0
    override class var layerClass: AnyClass { return CAGradientLayer.self }
    var gradientLayer: CAGradientLayer { return layer as! CAGradientLayer }
    func updatePoints() {
        if horizontalMode {
            gradientLayer.startPoint = diagonalMode ? CGPoint(x: 1, y: 0) : CGPoint(x: 0, y: 0.5)
            gradientLayer.endPoint   = diagonalMode ? CGPoint(x: 0, y: 1) : CGPoint(x: 1, y: 0.5)

        } else {
            gradientLayer.startPoint = diagonalMode ? CGPoint(x: 0, y: 0) : CGPoint(x: 0.5, y: 0)
            gradientLayer.endPoint   = diagonalMode ? CGPoint(x: 1, y: 1) : CGPoint(x: 0.5, y: 1)
        }
    }
    func updateLocations() {
        gradientLayer.locations = [startLocation as NSNumber, endLocation as NSNumber]
    }
    func updateColors() {
        gradientLayer.colors    = [startColor.cgColor, endColor.cgColor]
    }
    override func layoutSubviews() {
        super.layoutSubviews()
        gradientLayer.drawsAsynchronously = true
        gradientSet.append([startColor.cgColor, endColor.cgColor])
        gradientSet.append([endColor.cgColor, startColor.cgColor])
        updatePoints()
        updateLocations()
        updateColors()
    }
}