Swift 4中的全屏UIImage

Question

我有一个UICollectionView，其中包含包含UIImages的单元格。这是我的didSelectIndex方法来抓取图像并将其全屏显示。

override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    let media = self.media[indexPath.row]
    guard let photoURL = URL(string: media.photoURL) else { return }

    // Get the image from the cache
    if let image = mediaCache.object(forKey: photoURL.absoluteString as AnyObject) as? UIImage {
        let imageView = UIImageView(image: image)
        imageView.frame = UIScreen.main.bounds
        imageView.backgroundColor = .black
        imageView.contentMode = .scaleAspectFill
        imageView.clipsToBounds = true
        imageView.isUserInteractionEnabled = true

        self.navigationController?.isNavigationBarHidden = true
        self.tabBarController?.tabBar.isHidden = true

        let dismissTap = UITapGestureRecognizer(target: self, action: #selector(dismissFullscreenImage))
        imageView.addGestureRecognizer(dismissTap)

        self.view.addSubview(imageView)
    }
}

但是，将内容模式从scaleAspectFill更改为scaleAspectFit并不能解决问题。图像不适合UIImageView框架。