【Swift UIKit】画像をカメラロールから選択/保存/取得/削除する方法！

├── AppData
│ ├── Documents
│ ├── Library
│        ├── Application Support
│        ├── Caches
│        ├── Preferences
│        ├── Saved Application State
│        └── SplashBoard
│ ├── SystemData
│ └── tmp

class ImageViewController: UIViewController {
    
    // MARK: - Outlet
    @IBOutlet  weak var imageView: UIImageView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
    }

    // MARK: - パスの構築
    func docURL(_ fileName:String) -> URL? {
        do {
            // Docmentsフォルダ
            let docsUrl = try FileManager.default.url(
                for: .documentDirectory,
                in: .userDomainMask,
                appropriateFor: nil,
                create: false)
            // URLを構築
            let url = docsUrl.appendingPathComponent(fileName)
            return url
        } catch {
            return nil
        }
    }
    
    // MARK: - 選択
    @IBAction  func selectImage() {
    }
    // MARK: - 保存
    @IBAction  func saveImage() {
    }
    // MARK: - 取得
    @IBAction  func loadImage() {
    }
    // MARK: - 削除
    @IBAction  func deleteImage() {
    }
}

import UIKit

class ImageViewController: UIViewController {    
    override func viewDidLoad() {
        super.viewDidLoad()
    }
}

extension ImageViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        let image = info[.originalImage] as! UIImage // 選択された画像を取得
        imageView.image = image      // imageViewプロパティに格納
        self.dismiss(animated: true) // 選択画面を閉じる 
    }
}

@IBAction  func selectImage() {
    if UIImagePickerController.isSourceTypeAvailable(.photoLibrary) {
        let pickerView = UIImagePickerController()
        pickerView.sourceType = .photoLibrary
        pickerView.delegate = self
        self.present(pickerView, animated: true)
    }
}

@IBAction  func saveImage() {
  guard let imageData = imageView.image?.jpegData(compressionQuality: 1.0) else {
      return
  }
  do {
      let name = "Test" 
      try imageData.write(to: docURL("\(name).jpg")!)
      print("画像を保存できました")
  } catch {
      print("\(error)")
  }
}

@IBAction  func loadImage() {
  let name = "Test"
  let path = docURL("\(name).jpg")!.path
  if FileManager.default.fileExists(atPath: path) {
      if let image = UIImage(contentsOfFile: path) {
          imageView.image = image
      }else {
          print("読み込みに失敗しました")
      }
  }else {
      print("画像が見つかりませんでした")
  }
}

@IBAction  func deleteImage() {
    let name = "Test"
    let url = docURL("\(name).jpg")!
    do {
        try FileManager.default.removeItem(at: url)
    } catch {
        print("削除失敗")
    }
}

@MainActor  protocol UIImagePickerControllerDelegate

optional func imagePickerController(
    _ picker: UIImagePickerController,
    didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]
)

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    let image = info[.originalImage] as! UIImage // 選択された画像を取得
    imageView.image = image      // imageViewプロパティに格納
    self.dismiss(animated: true) // 選択画面を閉じる 
}

@MainActor  class UIImagePickerController : UINavigationController

if UIImagePickerController.isSourceTypeAvailable(.photoLibrary) {
    let pickerView = UIImagePickerController()
    pickerView.sourceType = .photoLibrary
    pickerView.delegate = self
    self.present(pickerView, animated: true)
}

class func isSourceTypeAvailable(_ sourceType: UIImagePickerController.SourceType) -> Bool

let pickerView = UIImagePickerController()
pickerView.sourceType = .photoLibrary
pickerView.delegate = self
self.present(pickerView, animated: true)