Swift 3.0：如何从应用程序保存用户的图像ImagePicker

Question

我想让用户从他们的画廊或相机中选择一个图像，然后将其上传到应用程序。这有效，但唯一的问题是它不会将它保存在应用程序中。只要用户关闭应用程序，用户选择的图像就会消失。我也没有任何保存功能，因为我不知道如何实现它。

我在Swift 3.0中使用Xcode 8.3.2。这是下面的代码：

import UIKit 

class ViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate { 

    @IBOutlet weak var imageView: UIImageView! 
    override func viewDidLoad() { 
     super.viewDidLoad() 
     // Do any additional setup after loading the view, typically from a nib. 
    } 

    @IBAction func chooseImage(_ 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 

      if UIImagePickerController.isSourceTypeAvailable(.camera) { 
       imagePickerController.sourceType = .camera 
       self.present(imagePickerController, animated: true, completion: nil) 
      }else{ 
       print("Camera not available") 
      } 


     })) 

     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: [String : Any]) { 
     let image = info[UIImagePickerControllerOriginalImage] as! UIImage 

     imageView.image = image 

     picker.dismiss(animated: true, completion: nil) 
    } 

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





    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 


} 

Answer 1

记得保存图像，你需要存储的图像作为NSData的

 // Code to store image 
    let defaults = UserDefaults.standard 

    // To save as data: 

    // From StoryBoard, if you want to save "image" data on the imageView of 
    // MainStoryBoard, following codes will work. 

    let image = UIImagePNGRepresentation(imageView.image!) as NSData? 
    defaults.set(image, forKey: "test") // saving image into userdefault 


    // for retrieving the image 

    if (UserDefaults.standard.object(forKey: "test") as? NSData) != nil { 
     let photo = UserDefaults.standard.object(forKey: "test") as! NSData 
     img2.image = UIImage(data: photo as Data) // img2 set your imageview on which you want photo to appear 

     // Now you can set img2.image 
    } 

编辑

如何在代码中使用

func imagePickerController(_ picker: UIImagePickerController, 
    didFinishPickingMediaWithInfo info: [String : Any]) { 
    let defaults = UserDefaults.standard 
    let image = info[UIImagePickerControllerOriginalImage] as! UIImage 

    imageView.image = image 
    let saveImage = UIImagePNGRepresentation(image!) as NSData? 
    defaults.set(saveImage, forKey: "test") // saving image into userdefault 


    picker.dismiss(animated: true, completion: nil) 
} 

而且在你看来确实加载使用检索方法 如果图像存在并且在nsdata forma那么只有它会显示保存图像。而已。

Answer 2

你可以在你的文档目录中保存以下功能图像

func saveImageDocumentDirectory(tempImage:UIImage){ 

    let documentsDirectoryURL = try! FileManager().url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true) 
    let fileURL = documentsDirectoryURL.appendingPathComponent("ImageName.png") 
     do { 
      try UIImagePNGRepresentation(tempImage)?.write(to: fileURL) 
     } catch { 
      print(error) 
     } 
} 

要检索图片，您可以使用

func getImage()->URL?{ 

    let documentsDirectoryURL = try! FileManager().url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: true) 
    let fileURL = documentsDirectoryURL.appendingPathComponent("ImageName.png") 

    if FileManager.default.fileExists(atPath: fileURL.path){ 
     return fileURL 
    }else{ 
     return nil 
    } 
} 

你可以用你喜欢的任何名称和店铺形象与不同的名称来存储多个图像。