CODEWITHSUNDEEP
iosobjective-cnsuserdefaults
Alex Wulff
Alex Wulff

Reputation: 2067

Problems with saving an int in NSUserDefaults iOS

I am using the below code to save an int and some other stuff into NSUserDefaults from my AppDelegate. The other array that I'm saving is full of objects that conform to NSCoding, so I don't think that that's an issue. If the current place is not zero, then that means that there is a session in progress, so all the data is loaded. When saving my data, it only saves if the current place is not zero which indicates that there is a session in progress. I know this calls when I exit the app on my physical device because the NSLog message appears in the debugger.

- (void)applicationDidEnterBackground:(UIApplication *)application {
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.

if (self.currentPlace != 0) {
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSMutableArray *arr = self.places; // set value
    NSData *data = [NSKeyedArchiver archivedDataWithRootObject:arr];
    [defaults setObject:data forKey:@"places"];
    [defaults setInteger:self.currentPlace forKey:@"current"];
    NSLog(@"Saving and Quitting b/c we have a place verified!");
    [defaults synchronize];
}
}

- (void)applicationWillEnterForeground:(UIApplication *)application {
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

NSInteger myInt = [defaults integerForKey:@"current"];

self.currentPlace = (int)myInt;

if (self.currentPlace != 0) {
    NSData *data = [defaults objectForKey:@"places"];
    NSArray *arr = [NSKeyedUnarchiver unarchiveObjectWithData:data];
    self.places = [arr mutableCopy];
    NSLog(@"Current Place: %i",self.currentPlace);
}

}

I am using my AppDelegate to store data that can be accessed from multiple screens in my app. In the first ViewController, the user is presented with a menu. If the appDelegate's currnentPlace value is not 0, then the option to continue with the loaded data from the AppDelegate is presented. However, this option is never presented. I check the currentPlace int's value using the following in my first view controller:

AppDelegate *delegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];

// Do any additional setup after loading the view, typically from a nib.
[self setupViews];
self.spinner.alpha = 0;
NSLog(@"Current %i",delegate.currentPlace);

if (delegate.currentPlace == 0) {
    self.continueButton.enabled = false;
    self.continueButton.alpha = 0.5;
}
else if (delegate.currentPlace != 0) {
    self.continueButton.enabled = true;
    self.continueButton.alpha = 1;
}

If anyone could see what I'm doing wrong it would be greatly appreciated.

Upvotes: 0

Views: 119

Answers (2)

kslcam
kslcam

Reputation: 101

Move your data restoration code block into a method, as below:

   - (void)restoreData {
       NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
       NSInteger myInt = [defaults integerForKey:@"current"];

       self.currentPlace = (int)myInt;

       if (self.currentPlace != 0) {
         NSData *data = [defaults objectForKey:@"places"];
         NSArray *arr = [NSKeyedUnarchiver unarchiveObjectWithData:data];
         self.places = [arr mutableCopy];
         NSLog(@"Current Place: %i",self.currentPlace);
       }
    }

Then call this method in application:didFinishLaunchingWithOptions: and applicationWillEnterForeground: methods in AppDelegate.

Upvotes: 1

iYoung
iYoung

Reputation: 3622

You need to use 

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

in you controller in which you are making the object of AppDelegate class.

If still you are not able to get current value then just store the value in user default as a string and when you acess it, convert it in appropriate data type which you want. Might be this could help you.

Upvotes: 1

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