How to set a Custom Image as ViewController Background - swift

Question

I have created a button that allows me to set an image from the camera roll as the ViewController background (imageView is the background view), but I need to save it and reload it when ViewController loads.
class ViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
#IBOutlet weak var backgroundSelectionView: UIView!
#IBOutlet weak var imageView: UIImageView!
#IBAction func imageButton(_ sender: UIButton) {
let imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.sourceType = .photoLibrary
imagePicker.allowsEditing = false
present(imagePicker, animated: true, completion: nil)
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
if let image = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
imageView.image = image
}
self.dismiss(animated: true, completion: nil)
}
}
I think I should use paths (I read it somewhere but I don't know how to do that since I can't find anything). Could you provide advice on how to save and load a CUSTOM image (not a specific one that you manually select and import in your code, I can already do that?)

Answer 1

Welcome to StackOverflow!
The easiest way to do this would likely be to save the image to disk once you have picked it and restore it when ViewController loads.
To save the image, use FileManager and save to the app's document storage:
/// Saves a background image to disk
/// - Parameter image: The background image to save to disk
/// - Returns: true if successful, false otherwise
func saveBackgroundImage(image: UIImage) -> Bool {
// make sure that the image can be transformed into data (assuming PNG)
guard let data = image.pngData() ?? imageView.image?.pngData() else {
return false
}
// ensure that you can write to the document director
guard let directory = FileManager.default.urls(for: .documentDirectory,
in: .userDomainMask).first else {
return false
}
// write the file
do {
try data.write(to: directory.appendingPathComponent("backgroundImage.png")!)
return true
} catch {
print(error.localizedDescription)
return false
}
}
Now, you need a way to retrieve the file:
/// Retrieves the saved background image
/// - Returns: The background image from disk if it exists, or nil
func getSavedBackgroundImage() -> UIImage? {
if let dir = FileManager.default.urls(for: .documentDirectory,
in: .userDomainMask).first {
return UIImage(contentsOfFile: URL(fileURLWithPath: dir.absoluteString).appendingPathComponent("backgroundImage.png").path)
}
return nil
}
Inside your imagePickerController(picker: didFinishPickingMediaWithInfo:) method, when you set the image on imageView, save the background image by calling self.saveBackgroundImage(image: image). If you are not checking the boolean that is returned from saveBackgroundImage(image:), then call it as follows:
let _ = self.saveBackgroundImage(image: image)
to prevent a "Result unused" warning.
Now, implement your viewDidLoad, which is where you will attempt to load the image:
override func viewDidLoad() {
super.viewDidLoad()
if let backgroundImage = self.getSavedBackgroundImage() {
// set the background image on the `imageView`
self.imageView.image = backgroundImage
}
}

Answer 2

Please set backgroundImage as below,
override func viewDidLoad() {
super.viewDidLoad()
assignbackground()
}
func assignbackground(){
let background = UIImage(named: backgroundImage)
var imageView : UIImageView!
imageView = UIImageView(frame: view.bounds)
imageView.contentMode = UIViewContentMode.ScaleAspectFill
imageView.clipsToBounds = true
imageView.image = background
imageView.center = view.center
view.addSubview(imageView)
self.view.sendSubviewToBack(imageView)
}
Please user remaining code as it is as #Leejay Schmidt's code