【Swift/PhotoKit】PHPickerViewControllerで画像を取得する方法！写真アプリの操作

import Photos
import PhotosUI

PhotoKitViewController.swift
import UIKit
import PhotosUI

class PhotoKitViewController: UIViewController {
    
    let imageView = UIImageView()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        let button = UIButton()
        button.backgroundColor = .orange
        button.frame = CGRect(x: UIScreen.main.bounds.width/3, y: 200, width: UIScreen.main.bounds.width/3, height: 50)
        button.setTitle("画像を選択", for: .normal)
        button.addTarget(self, action: #selector(showPhotoPicker), for: .touchUpInside)
        view.addSubview(button)    

        imageView.frame =  CGRect(x: 0, y: 400, width: UIScreen.main.bounds.width, height: 300)
        view.addSubview(imageView)
    }
    
    @objc  func showPhotoPicker() {
      // ピッカーの構成(フィルタリングなど)を定義
      // その構成を元にPHPickerViewControllerを構築
    }
}

定義
struct PHPickerConfiguration {
    var filter: PHPickerFilter? // フィルタリング
    var selectionLimit: Int     // 選択可能な数
}

struct PHPickerFilter {
    // MARK: - constant
    static let bursts: PHPickerFilter // 複数の高速写真を含むアセット
    static let cinematicVideos: PHPickerFilter // 被写界深度が浅く、フォーカスの遷移が激しい動画
    static let depthEffectPhotos: PHPickerFilter // 深度情報を持つ写真
    static let images: PHPickerFilter // 画像 ( Live Photosを含む ) 
    static let livePhotos: PHPickerFilter // Live Photos 
    static let panoramas: PHPickerFilter // パノラマ写真を
    static let screenRecordings: PHPickerFilter // 画面記録
    static let screenshots: PHPickerFilter // スクリーンショット
    static let slomoVideos: PHPickerFilter // スローモーション動画
    static let timelapseVideos: PHPickerFilter // タイムラプス
    static let videos: PHPickerFilter // 動画アセット

    // MARK: - method
    static func all(of: [PHPickerFilter]) -> PHPickerFilter // 指定したフィルターのみを含むフィルターを作成
    static func not(PHPickerFilter) -> PHPickerFilter // 指定したフィルターを除外するフィルターを作成
    static func any(of: [PHPickerFilter]) -> PHPickerFilter // 配列内のフィルターを組み合わせたフィルターを作成
}

PhotoKitViewController.swift > showPhotoPicker()
var configuration = PHPickerConfiguration()
configuration.filter = PHPickerFilter.images
// 例 configuration.filter = PHPickerFilter.any(of: [.livePhotos, .videos])
configuration.selectionLimit = 1

PhotoKitViewController.swift > showPhotoPicker()
let picker = PHPickerViewController(configuration: configuration)
picker.delegate = self
present(picker, animated: true, completion: nil)

extension PhotoKitViewController: UINavigationControllerDelegate, PHPickerViewControllerDelegate {
  // 
}

PhotoKitViewController.swift
import UIKit
import PhotosUI

class PhotoKitViewController: UIViewController {
    
    let imageView = UIImageView()

    override func viewDidLoad() {
        super.viewDidLoad()
        let button = UIButton()
        button.backgroundColor = .orange
        button.frame = CGRect(x: UIScreen.main.bounds.width/3, y: 200, width: UIScreen.main.bounds.width/3, height: 50)
        button.setTitle("画像を選択", for: .normal)
        button.addTarget(self, action: #selector(showPhotoPicker), for: .touchUpInside)
        view.addSubview(button)    
    }

    @objc  func showPhotoPicker() {
        var configuration = PHPickerConfiguration()
        configuration.filter = PHPickerFilter.images
        configuration.selectionLimit = 1
        let picker = PHPickerViewController(configuration: configuration)
        picker.delegate = self
        present(picker, animated: true, completion: nil)
    }
}

extension PhotoKitViewController: UINavigationControllerDelegate, PHPickerViewControllerDelegate {
  // 
}

PhotoKitViewController.swift
extension PhotoKitViewController: UINavigationControllerDelegate, PHPickerViewControllerDelegate {
    func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
        
        if let itemProvider = results.first?.itemProvider{
            if itemProvider.canLoadObject(ofClass: UIImage.self) {
                itemProvider.loadObject(ofClass: UIImage.self) { [weak self] image, error in
                    guard let image = image as? UIImage else {
                        return
                    }
                    DispatchQueue.main.async {
                        self?.imageView.image = image
                    }
                }
            }
        }
        self.dismiss(animated: true)
    }
}