渐变颜色不适用于SWReveal视图控制器内容视图

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建一个新的UIView作为内容视图
        let contentView = UIView(frame: self.view.bounds)
        self.view.addSubview(contentView)
        
        // 创建一个CAGradientLayer作为渐变颜色图层
        let gradientLayer = CAGradientLayer()
        gradientLayer.frame = contentView.bounds
        
        // 配置渐变颜色
        gradientLayer.colors = [UIColor.red.cgColor, UIColor.blue.cgColor]
        gradientLayer.locations = [0.0, 1.0]
        
        // 将渐变颜色图层添加到内容视图的图层中
        contentView.layer.addSublayer(gradientLayer)
    }
}