在iphone plus设备上不覆盖图像ios swift 3的渐变

Question

我创建了一个视图，它保存我的渐变，但渐变不适用于整个图像/视图。通常在iPhone plus设备中观察到此问题。

import UIKit

class MainViewController: UIViewController {
    @IBOutlet weak var imageViewBanner: UIImageView!
    @IBOutlet weak var viewGradient: UIView!

    let color1 = UIColor(red: 48.0/255.0, green: 178.0/255.0, blue: 166.0/255.0, alpha: 1.0)
    let color2 = UIColor(red: 82.0/255.0, green: 96.0/255.0, blue: 169.0/255.0, alpha: 1.0)

    override func viewDidLoad() {
        super.viewDidLoad()

        self.viewGradient.frame = self.viewGradient.bounds
        let gradientLayer = CAGradientLayer()
        gradientLayer.colors = [color1.cgColor, color2.cgColor]
        gradientLayer.locations = [0.0 , 1.0]
        gradientLayer.startPoint = CGPoint(x: 0.0, y: 1.0)
        gradientLayer.endPoint = CGPoint(x: 1.0, y: 1.0)
        gradientLayer.frame = CGRect(x: 0.0, y: 0.0, width: self.view.frame.size.width, height: self.viewGradient.frame.size.height)
        self.viewGradient.layer.insertSublayer(gradientLayer, at: 0)
    }
}