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nicolaswilhelm
6,824 PointsHelp with NSUserDefaults
I am having trouble with NSUserDefaults. Here is the code:
var money = 0
let userDefaults = NSUserDefaults.standardUserDefaults()
userDefaults.setValue(money, forKey: "money")
userDefaults.synchronize()
and then to read it:
if let score = userDefaults.valueForKey("score") {
moneyLabel.text = "Money:\(money)"
}
else {
money = 0
}
What happens is that when I load the money number it appears on the label like I wanted to but, when more money was added the number reset to zero. How do I make it so that any extra money made is added to the label instead of it reseting to zero?
2 Answers
Michael Hulet
47,913 PointsWait, I think I just noticed your problem. You're accessing a value with a different key than you're setting it with. This line:
userDefaults.setValue(money, forKey: "money")
needs to use the same String as this line:
if let score = userDefaults.valueForKey("score") {
Here's a fixed version of my 2nd referenced line:
if let score = userDefaults.valueForKey("money") {
When you use this alongside my first answer (preferably the 2nd part of my first answer, as that one writes to the disk less frequently), your problems should go away
Michael Hulet
47,913 PointsIt sounds like you're setting money and storing it in NSUserDefaults once, whereas you should update its NSUserDefaults representation every time money changes, like this:
var money{
didSet{
let userDefaults = NSUserDefaults.standardUserDefaults()
userDefaults.setValue(money, forKey: "money")
userDefaults.synchronize()
}
}
Alternatively, you can save the current value of your money variable whenever your view is about to disappear, like this:
override func viewWillDisappear(animated: Bool) -> Void{
super.viewWillDisappear(animated)
let userDefaults = NSUserDefaults.standardUserDefaults()
userDefaults.setValue(money, forKey: "money")
userDefaults.synchronize()
}
nicolaswilhelm
6,824 PointsI have tried both but, it has the same problem that I had with my code before.
Michael Hulet
47,913 PointsCould you post the entire content of your class, then?
nicolaswilhelm
6,824 PointsI'd prefer not to since the class this part is apart of, is a class within an app I would like to release. Is there any other way to solve it?
Michael Hulet
47,913 PointsIt'd be pretty hard. No one's going to steal your app (it'd be impossible to with just one class). In fact, open-sourcing is a really popular thing in software development. I put all of my code on my GitHub. In fact, the only app I have on the App Store has the entirety of its code posted for anyone to see and use in a repository on my GitHub. It's an entirely safe and frequently encouraged thing to do
nicolaswilhelm
6,824 Pointsnicolaswilhelm
6,824 PointsThat seems to have fixed the problems. Thanks!