Swift で UIImagePickerController を使って写真を読み込む

検証環境:
Xcode 11.4
Swift 5.2

Swift で UIImagePickerController を使って写真を読み込むための最小コードサンプルです。

import UIKit

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
    }
    
    @IBAction func handleButton(_ sender: UIButton) {
        
        guard UIImagePickerController.isSourceTypeAvailable(.photoLibrary) else {
            return
        }
        
        let picker = UIImagePickerController()
        picker.sourceType = .photoLibrary // 他に .camera, .savedPhotosAlbum がある
        picker.delegate = self
        //picker.allowsEditing = true // 写真選択後に正方形にクロップする編集画面に遷移するか
        present(picker, animated: true)
    }
}

extension ViewController: UIImagePickerControllerDelegate & UINavigationControllerDelegate {
    
    func imagePickerController(_ picker: UIImagePickerController,
                               didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]) {
        print("didFinishPickingMediaWithInfo. ", info)
        
        picker.dismiss(animated: true) {
            if let image = info[.originalImage] as? UIImage {
                // do stuff
            }
        }
    }
    
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        print("imagePickerControllerDidCancel.")
        picker.dismiss(animated: true)
    }
}