在Swift中使用NSUserDefaults保存NSMutableArray返回Nil

Question

I have a NSMutableArray . Here is how I save it with NSUserDefaults :

var defaults = NSUserDefaults.standardUserDefaults()
defaults.setObject(downloadedFile as NSMutableArray, forKey: "myKey")

And here how I retrieve it:

var downloadedFilesFromUserDefaults:NSMutableArray = defaults.objectForKey("myKey") as NSMutableArray

Answer 1

take look at this and try to save you array like this! as this worked perfectly!

var arr:NSMutableArray = NSMutableArray(objects: "ASD","aSd")
    NSUserDefaults.standardUserDefaults().setObject(arr, forKey: "Array")
    NSUserDefaults.standardUserDefaults().synchronize()

on button click

NSLog("%@", NSUserDefaults.standardUserDefaults().objectForKey("Array") as NSMutableArray)

Answer 2

看来我需要以某种方式快速释放我的对象，以确保我的对象不为零。