NSUserDefaults返回nil

Question

Im trying to save an object to NSUserdefaults and then extract the same object.

//        let raw: AnyObject! = defaults.valueForKey("testKey")
//        let data = raw as NSData
//        
//        self.Report = NSKeyedUnarchiver.unarchiveObjectWithData(data) as DayReport
//        
//        println(Report.Day)


    Report.Day = "Mon"

    let data = NSKeyedArchiver.archivedDataWithRootObject(self.Report)

    println(data)

    defaults.setObject(data, forKey: "testKey")
    defaults.synchronize()

In this piece of code I save the object Report into NSUserDefaults encoded to NSData . DayReport is the type of Report

But when I switch the comment sections so the upper part of the code is not commented and the lower part is, the let var = (nil) and the program crashes. Why?

DayReport has the NSCoding protocol.

Update

I added this:

    defaults.setObject(data, forKey: "testKey")
    defaults.synchronize()

    println(defaults.objectForKey("testKey"))

And it prints out nil, so it isnt getting saved properly but the data is not nil.

Answer 1

You should not be using .valueForKey("testKey") because this is using KVC to try to get a key that doesn't exist.

Instead you should be using .objectForKey("testKey") .

Answer 2

Here is the code for set value to NSuserDefaults...

 [[NSUserDefaults standardUserDefaults] setInteger:1  forKey:@"your key"];//Remember your key to get data from NSuserDefaults
[[NSUserDefaults standardUserDefaults] synchronize];

code for get value from NSuserDefaults...

  int CheckTimer = [[NSUserDefaults standardUserDefaults] integerForKey:@"your key"];

I hope this help you....