Manually drawing a gradient in iPhone apps?

Question

If I have two UIColors, what\'s the best way to draw an even gradient between them over an arbitrarily-sized area?

I am guessing you would create a UIView subclass a

Answer 1

Same-ish solution as @Anton Chikin but a little more robust. Notice the override of layerClass... this way, you don't have to worry about setting the frame and the frame is automatically updated upon rotation & resize.

class GradientView: UIView {

    var colorA : UIColor = UIColor.greenColor() {
        didSet { updateGradient() }
    }
    var colorB : UIColor = UIColor.blueColor() {
        didSet { updateGradient() }
    }

    override class func layerClass() -> AnyClass {
        return CAGradientLayer.self
    }

    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        updateGradient()
    }

    func updateGradient() {
        if let gLayer = layer as? CAGradientLayer {
            gLayer.colors = [colorA.CGColor, colorB.CGColor]
        }
    }

}

If you're using IB, you can set the properties via "User Defined Runtime Attributes".

If you're not using IB, use the other initializer.