iOS以编程方式渐变

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建渐变图层
        let gradientLayer = CAGradientLayer()
        gradientLayer.frame = view.bounds
        
        // 设置渐变颜色数组
        gradientLayer.colors = [UIColor.red.cgColor, UIColor.blue.cgColor]
        
        // 设置渐变颜色位置
        gradientLayer.locations = [0.0, 1.0]
        
        // 设置渐变起始点和结束点
        gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.0)
        gradientLayer.endPoint = CGPoint(x: 1.0, y: 1.0)
        
        // 将渐变图层添加到视图中
        view.layer.addSublayer(gradientLayer)
    }
}