Swift 3.0：如何通过 imagePicker 在应用程序中保存用户图像

Question

我正在尝试让用户从他们的画廊或相机中选择一张图片，然后将其上传到应用程序。这可行，但唯一的问题是它不会将其保存在应用程序中。一旦用户关闭应用程序，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。

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

记得保存图片你需要将图片存储为NSData

      // 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
    }

已编辑

如何在你的代码中使用

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)
}

并且在您看来确实加载使用了检索方法如果图像存在且为 nsdata 格式，则只有它会显示保存图像。就是这样。

Answer 2

您可以使用以下功能将图像保存在您的文档目录中

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)
        }
}

要检索图像，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
    }
}

您可以使用任何您喜欢的名称，并使用不同的名称存储图像以存储多个图像。

Swift 3.0：如何通过 imagePicker 在应用程序中保存用户图像

Swift 3.0: How to save a user's image in the app from an imagePicker

uiimageview

uiimagepickercontroller

ios

swift3

xcode8