Swift2 背景グラデーションの各種設定

背景グラデーション

色の設定と角度の設定

ViewController.sift

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        let gradientLayer = CAGradientLayer()
        let angle:String = "0"
        
        let start:CGPoint
        let end:CGPoint
        
        
        gradientLayer.frame = self.view.bounds
        
        // グラデーションの色
        let red = UIColor.redColor().CGColor
        let green = UIColor.greenColor().CGColor
        let yellow = UIColor.yellowColor().CGColor
        let blue = UIColor.blueColor().CGColor
        let purple = UIColor.purpleColor().CGColor
        
        // グラデーションの角度
        switch (angle) {
        case "0":
            start = CGPointMake(0.5, 0.0);
            end = CGPointMake(0.5, 1.0);
            break;
        case "45":
            start = CGPointMake(1.0, 0.0)
            end = CGPointMake(0.0, 1.0);
            break;
        case "90":
            start = CGPointMake(1.0, 0.5);
            end = CGPointMake(0.0, 0.5);
            break;
        default:
            start = CGPointMake(0.5, 0.0)
            end = CGPointMake(0.5, 1.0)
            break;
        }
        
        gradientLayer.colors = [red, green, yellow, blue, purple]
        gradientLayer.locations = [0.0, 0.25, 0.5, 0.75, 1.0]
        gradientLayer.startPoint = start
        gradientLayer.endPoint = end
        // self.view.layer.addSublayer(gradientLayer)
        self.view.layer.insertSublayer(gradientLayer, atIndex: 0)
    }
}