我的应用关闭后保存变量（快速）

问题描述：

我正在尝试在Xcode中保存变量，以便即使在应用程序关闭后也能保存，但是当我访问它时，我从几个不同的类和文件中执行它，并且我在更改变量的值时我访问它。因此类似的线程不完全适用，要存储的值是一个字符串，这是我到目前为止的代码：

I'm trying to save a variable in Xcode so that it saves even after the app has closed, how ever when I access it I do it from a several different classes and files, and I change the value of the variable when I access it. Therefore similar threads do not completely apply, the value to be stored is a string and here is the code I have up until now:

var defaults: NSUserDefaults = NSUserDefaults.standardUserDefaults()
defaults.setObject(Token, forKey: "") as! String

我相信这是正确的格式，但我不知道如何调用它来改变因为当我尝试时，我收到一条错误消息，说明预期的声明。

I believe this is the correct format, but I don't know how to call it to change it because when I try I get an error message saying expected declaration.

无论如何，任何帮助都会非常感激。

Anyway any help would be very much appreciated.

答

首先，您必须指定一个唯一键来存储变量（在示例 MyKey 中）。

First of all you have to specify an unique key to store the variable (in the example MyKey ).

在 AppDelegate> applicationDidFinishLaunching 使用默认值注册密钥。

好处是你可以使用非可选变量，并且你有一个已定义的默认值。

In AppDelegate > applicationDidFinishLaunching register the key with a default value.
The benefit is you can use a non-optional variable and you have a defined default value.

let defaults = UserDefaults.standard
let defaultValue = ["MyKey" : ""]
defaults.register(defaults: defaultValue)

现在你可以从各处读取密钥的价值

Now you can from everywhere read the value for the key

let defaults = UserDefaults.standard
let token = defaults.string(forKey: "MyKey")

并保存

let defaults = UserDefaults.standard
defaults.set(token, forKey: "MyKey")

我的应用关闭后保存变量（快速）

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