swift4 AlamofireとImageViewでURLから取得した画像を拡大表示

http://kimagureneet.hatenablog.com/entry/2019/02/27/025807
ここでやったのとほとんど同じ。ちがいは以下だけ
・URLからの画像を表示
・キャッシュとか考えるとAlamofireImage使う

import UIKit                                                                                                                                                                                                                                 
import AlamofireImage                                                                                                                                                                                                                        
import ImageViewer                                                                                                                                                                                                                           

class ViewController: UIViewController, GalleryItemsDataSource {                                                                                                                                                                             

    var galleyItem: GalleryItem!                                                                                                                                                                                                             

    override func viewDidLoad() {                                                                                                                                                                                                            
        super.viewDidLoad()                                                                                                                                                                                                                  

        let imageView = UIImageView(frame: CGRect(x: 100, y: 100, width: view.frame.width - 100*2, height: 200))                                                                                                                             
        imageView.contentMode = UIImageView.ContentMode.scaleAspectFill                                                                                                                                                                      
        view.addSubview(imageView)                                                                                                                                                                                                           

        let url = "https://example.com/path/to/img"
        imageView.af_setImage(withURL: URL(string: url)!)                                                                                                                                                                                    
        galleyItem = GalleryItem.image{ $0(imageView.image) }                                                                                                                                                                                

        imageView.isUserInteractionEnabled = true                                                                                                                                                                                            
        let recognizer = UITapGestureRecognizer(target: self, action: #selector(self.onTap(_:)))                                                                                                                                             
        imageView.addGestureRecognizer(recognizer)                                                                                                                                                                                           
    }

    @objc func onTap(_ sender: UIImageView) {                                                                                                                                                                                                
        let galleryViewController = GalleryViewController(startIndex: 0, itemsDataSource: self, configuration: [.deleteButtonMode(.none), .seeAllCloseButtonMode(.none), .thumbnailsButtonMode(.none)])                                      
        self.present(galleryViewController, animated: true, completion: nil)                                                                                                                                                                 
    }

    // MARK: GalleryItemsDataSource                                                                                                                                                                                                          
    func itemCount() -> Int {                                                                                                                                                                                                                
        return 1                                                                                                                                                                                                                             
    }

    func provideGalleryItem(_ index: Int) -> GalleryItem {                                                                                                                                                                                   
        return galleyItem                                                                                                                                                                                                                    
    }
}

ネット上の画像を表示することの方が多いのでコピペ用にメモした。以上です