storing background images in userdefaults - ios

Question

I need to be able to set the background image for this button. I need to store this so after the app closes the background image is the same.
eventsFirstButton.backgroundColor = UIColor(patternImage: UIImage(named: "events")!)

Answer 1

You could just save the state:
Correct answer:
UserDefaults.standard.set(true, forKey: "TestAnswer1")
//If the answer is incorrect set to false
On load:
if UserDefaults.standard.bool(forKey: "TestAnswer1") {
view.backgroundColor = UIColor.green
// or any other logic
} else {
view.backgroundColor = UIColor.red
// or any other logic
}

Answer 2

It's better to save it as base64string, you don't want to store large value to UserDefaults.
To encode UIImage use this:
let image = UIImage()
let data = image.pngData()
let imageBase64String = data?.base64EncodedString()
UserDefaults.standard.set(imageBase64String, forKey: "encodedImage")
And for decoding and retrieving UIImage use this:
if let imageBase64String = UserDefaults.standard.value(forKey: "encodedImage"),
let url = URL(string: String(format:"data:application/octet-stream;base64,%#",imageBase64String))
{
do
{
let data = try Data(contentsOf: url)
let image = UIImage(data: data)
}
catch let error
{
print("Error decoding image")
}
}
If you really need to save the PNG, JPEG images locally, use CoreData to store them on the device.

Answer 3

You can use UserDefaults to save your image
Save
if let image = eventsFirstButton.imageView?.image {
let imageData = image.pngData()
UserDefaults.standard.set(imageData, forKey: "imageData")
}
Retrieve
if let imageData = UserDefaults.standard.data(forKey: "imageData") {
print("IMG data: ", imageData)
// your code here
}