如何将 UIImage 转换为数据以将其保存在 coreData 中？斯威夫特 [重复]

Question

我想在 CoreData 中保存 UIImage，为此我创建了一个保存函数，其中包含两个参数，一个用于字符串类型，第二个用于“数据”类型的图像。我无法弄清楚如何将其转换为“数据”

import UIKit
import CoreData

protocol addDataVCDelegate: class {
    func updateInTable(person: Person?)
}

class addDataViewController: UIViewController, UITextFieldDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate {

    @IBOutlet weak var pName: UITextField!
    @IBOutlet weak var imageView: UIImageView!

    //MARK: 2 creating a delegate property
    weak var delegate: addDataVCDelegate?



    override func viewDidLoad() {
        super.viewDidLoad()
        pName.delegate = self

    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        _ = textField.text
        return true
    }


    @IBAction func addData(_ sender: UIButton) {

        delegate?.updateInTable(person: self.save(name: pName.text, image: UIImageView.data )) .

        dismiss(animated: true, completion: nil)
    }


    @IBAction func addPhoto(_ sender: Any) {

                let imagePickerController = UIImagePickerController()
                imagePickerController.delegate = self

                let actionSheet = UIAlertController(title: "Photo Source", message: "Choose a source", preferredStyle: .actionSheet)

                actionSheet.addAction(UIAlertAction(title: "Camera", style: .default, handler: {(action:UIAlertAction) in
                    imagePickerController.sourceType = .camera
                    self.present(imagePickerController, animated: true, completion: nil)
                }))
                actionSheet.addAction(UIAlertAction(title: "Photo Library", style: .default, handler: {(action:UIAlertAction) in
                    imagePickerController.sourceType = .photoLibrary
                    self.present(imagePickerController, animated: true, completion: nil)
                     }))

                actionSheet.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
                self.present(actionSheet, animated: true, completion: nil)


                }


        func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
            // Code here

            imageView.image = info[UIImagePickerController.InfoKey.originalImage] as? UIImage

           // imageView.image = image
          self.dismiss(animated: true, completion: nil)

        }

        func imagePickerControllerDidCancel(_ picker: UIImagePickerController){
            picker.dismiss(animated: true, completion: nil)
        }

     //To save data in Person 

    func save(name: String?, image: Data) -> Person?{

            guard let appDelegate =
                UIApplication.shared.delegate as? AppDelegate else {
                    return nil
            }

            // 1
            let managedContext =
                appDelegate.persistentContainer.viewContext

            // 2
            let entity =
                NSEntityDescription.entity(forEntityName: "Person",
                                           in: managedContext)!

            let person = NSManagedObject(entity: entity,
                                         insertInto: managedContext)

            // 3
            person.setValue(name, forKeyPath: "name")
            person.setValue(image, forKeyPath: "image")


            // 4
            do {
                try managedContext.save()
            } catch let error as NSError {
                print("Could not save. \(error), \(error.userInfo)")
            }
            return person as? Person
        }


    }

Answer 1

存储图像的更好解决方案是文件系统。您将图像保存到具有 id 的文件系统，并将该 id 存储在核心数据中。要检索您的图像，您从具有 id 的核心数据中获取实体，然后从您的文件系统（通常来自文档文件夹）中获取具有此 id 的图像。

Answer 2

Swift 解决方案

你可以使用类似下面的东西

let image = UIImage()//Add your image here
let data = image.pngData() //Returns Data?

然后尝试保存此数据

确保选中数据模型检查器中的“允许外部存储”选项 :)。

但我建议不要将图像/视频保存到 CoreData