在Xcode Swift上保存和加载整数

Question

I am trying to save an integer so it shows up after I switch the page or close the game. I made this to change the number but how do I save that number when I switch pages and load it when I go back to that page.

Change Code:

@IBAction func MoneyPress(sender: AnyObject) {

Money += 1

var MoneyNumberString:String = String(format: "Dollars:%i", Money)
self.DollarsLabel.text = (string: MoneyNumberString)

}

Answer 1

If it isn't a lot of data, the strategy I use to save data, pass it between pages, and persist it between app runs is to store the value in NSUserDefaults .

Setting A Value : When you first get or when you change the data, store it in NSUserDefaults .

@IBAction func MoneyPress(sender: AnyObject) {
    Money += 1
    var MoneyNumberString:String = String(format: "Dollars:%i", Money)
    self.DollarsLabel.text = (string: MoneyNumberString)
    let defaults: NSUserDefaults = NSUserDefaults.standardUserDefaults() //This class     variable needs to be defined every class where you set or fetch values from NSUserDefaults
    defaults.setObject(MoneyNumberString, forKey: "money")
    defaults.synchronize() //Call when you're done editing all defaults for the method.
}

Loading A Value : When you need to get the values, just grab it from NSUserDefaults .

@IBAction func loadButton(sender: UIButton) {
    let defaults: NSUserDefaults = NSUserDefaults.standardUserDefaults()
    var money = defaults.valueForKey("money") as? String
    dollarLabel.text! = money
}

To remove the stored data, all you need to do is call the removeObjectForKey function for each key previously set.

let defaults: NSUserDefaults = NSUserDefaults.standardUserDefaults()
defaults.removeObjectForKey("money")
defaults.synchronize()

Helpful Source on NSUserDefaults :

NSUserDefulats Class Reference: Link here .

Answer 2

You can use NSUserDefaults for this.

Save Value

NSUserDefaults.standardUserDefaults().setInteger(money, forKey: "MoneyKey");

---

Retrieve Value

NSUserDefaults.standardUserDefaults().integerForKey("MoneyKey");

So can retrieve the value in viewDidLoad and load the data:

override func viewDidLoad()
{
    super.viewDidLoad()
    loadWebView()
    var money = NSUserDefaults.standardUserDefaults().integerForKey("MoneyKey");
}

When you come to the view for the first time the value of money will be 0 .

---

Remove Value

If you need to remove a value from NSUserdefaults , you can use:

NSUserDefaults.standardUserDefaults().removeObjectForKey("MoneyKey")