无法在NSUserDefault中存储NSMutableDictionary

Question

Hi i know this question is asked before i wanted to know where i am going wrong in my code.So i am asking this question .. I am trying to store the value of nsmutabledictionary into nsuserdefaults ..

I have added uiswitch in uitableviewcell . so each time i turn ON uiswitch it should get stored in nsuserdefaults so that when i quit the app and reopen the app the switch which was ON the last time should be switched ON

- (void)viewDidLoad
{
    [super viewDidLoad];

    activeNotificationDictionary = [[NSMutableDictionary alloc]init];

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSData *data = [defaults objectForKey:@"theKey"];
    NSMutableDictionary *artworkDict = [NSKeyedUnarchiver unarchiveObjectWithData:data];

    artworkDict = activeNotificationDictionary;

}

-(void)notificationChangedForSymptom:(int)symptomIDNo withRemedyID:(int)remedyID isSelected:(BOOL)isSelected
{
    if (isSelected == YES)
    {        
        selectedSymptomID = symptomIDNo;
        selectedRemedyID = remedyID;

        if ([activeNotificationDictionary objectForKey:[NSNumber numberWithInt:symptomIDNo]] != nil)
       {
           UIAlertView *selectedNotification = [[UIAlertView alloc]initWithTitle:@"Reminder" message:@"Would you like to change the notification" delegate:nil cancelButtonTitle:@"Cancel" otherButtonTitles:@"Ok", nil];

           selectedNotification.delegate = self;
           NSLog(@" selected remedyID for symptom %@", activeNotificationDictionary);

           [selectedNotification show];

           NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

           NSDictionary *dict = [NSDictionary dictionaryWithObject:activeNotificationDictionary forKey:@"dictKey"];
           NSData *data = [NSKeyedArchiver archivedDataWithRootObject:dict];

           [defaults setObject:data forKey:@"theKey"];

           [defaults synchronize];

           NSLog(@"default value %@",defaults);

       }
       else 
       {

           [activeNotificationDictionary setObject:[NSNumber numberWithInt:RemedyID] forKey:[NSNumber numberWithInt:SymptomIDNo]];

       }

    }       

    else

      {
          [activeNotificationDictionary removeObjectForKey:[NSNumber numberWithInt:symptomIDNo]];
      }
}

Answer 1

When you encode a mutable dictionary just an immutable dictionary gets encoded, because NSMutableDictionary isn't overriding NSSecureCoding methods. So make a mutable copy of it:

NSData *data = [defaults objectForKey:@"theKey"];
NSMutableDictionary *artworkDict = [[NSKeyedUnarchiver unarchiveObjectWithData:data]mutableCopy];

EDIT

I suggest to initialize every default before the app starts, so for example:

+ (void) initialize // Inside the class storing the defaults
{
    NSUserDefaults* defaults= [NSUserDefaults standardUserDefaults];
    [defaults registerDefaults: @{ @"theKey":@{} } ];
}

If you want to synchronize all the defaults with the database, call synchronize:

[defaults synchronize];