如何在Swift中保存从UIImagePickerController中拾取的图像？

Question

我正在构建一个应用程序，让用户从其照片库中选取图像。我正在使用此代码来保存它。

func imagePickerController(picker: UIImagePickerController, didFinishPickingImage image: UIImage, editingInfo: [String : AnyObject]?) { 
    imgPicker.dismissViewControllerAnimated(true, completion: nil) 
    NSUserDefaults.standardUserDefaults().setValue(image, forKey: "bgImage") 
} 

func imagePickerControllerDidCancel(picker: UIImagePickerController) { 
    imgPicker.dismissViewControllerAnimated(true, completion: nil) 
} 

后来我想通了，你不能在NSUserDefaults的保存图像，但可以保存摄取的图像的路径，将其保存，并加载它，“如果让......”

但我不知道如何做到这一点（找到路径并保存）。这个想法是让用户选择视图背景图像，就像Whatsapp一样。

如果我错了，你不能存储路径，是否有任何简单的方法来保存采摘的图像，而无需使用在线服务器？

Answer 1

，可以保存和使用NSUserDefaults的检索：

//Save image 
let img = UIImage() //Change to be from UIPicker 
let data = UIImagePNGRepresentation(img) 
NSUserDefaults.standardUserDefaults().setObject(data, forKey: "myImageKey") 
NSUserDefaults.standardUserDefaults().synchronize() 

//Get image 
if let imgData = NSUserDefaults.standardUserDefaults().objectForKey("myImageKey") as? NSData { 
    let retrievedImg = UIImage(data: imgData) 
} 

或者你也可以读/写文件，如果你喜欢：

//Save image 
let img = UIImage() //Change to be from UIPicker 
let data = UIImagePNGRepresentation(img)! 
do { 
    let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String 
    try data.writeToFile("\(documentsPath)myImage", options: []) 

} catch { 
    print("Error") 
} 

//Get image 
do { 
    let documentsPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)[0] as String 
    let readData = try NSData(contentsOfFile: "\(documentsPath)myImage", options: []) 
    let retreivedImage = UIImage(data: readData) 
} 
catch { 
    print("Error") 
} 

斯威夫特3：

//Save image 
let data = UIImagePNGRepresentation(pickedImage)! 
do { 
    let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String 
    try data.write(to: URL(string: "\(documentsPath)/myImage")!, options: .atomic) 
} catch { 
    print("Error") 
} 

//Get image 
do { 
    let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String 
    let readData = try Data(contentsOf: URL(string: "\(documentsPath)/myImage")!) 
    let retreivedImage = UIImage(data: readData) 
} catch { 
    print("Error") 
} 

Answer 2

有两种方法，一种是你所描述的，但是非常混乱，我建议你采取的形象，成为图像数据，并将其存储在您的应用程序本地，如在SQLite数据库或用户默认数组。但是，将用户默认保存的数据不是一种好的做法。所以，我会在本地使用它，我不会用凌乱的sqlite代码来做，而是我会用核心数据来做到这一点。

class AddImageViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate { 

    @IBOutlet var popUpThePickerButton: UIButton! //click on this button to appear the imagePicker 
    @IBOutlet var addPictureButton: UIButton! //when this button clicked saveImage method is called and there you save the imageData wherever you want 

    let picker = UIImagePickerController() 
    var selectedImage : UIImage! 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     picker.delegate = self 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
    } 

    // when popUpThePickerButton is clicked 
    @IBAction func selectPictureFromPhotos(sender: UIButton) { 
     picker.editing = false 
     picker.sourceType = .PhotoLibrary 

     presentViewController(picker, animated: true, completion: nil) 
    } 

    func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) { 
     self.selectedImage = info[UIImagePickerControllerOriginalImage] as! UIImage 
     dismissViewControllerAnimated(true, completion: nil) 
    } 

    func imagePickerControllerDidCancel(picker: UIImagePickerController) { 
     dismissViewControllerAnimated(true, completion: nil) 
    } 

// then save this image data in your database and when you want to show that image you can just turn the image data to image again 

    @IBAction func saveImage(sender: UIButton) { 
     let imageData = UIImagePNGRepresentation(self.selectedImage) 
     //save this image data in database 
    } 
}