NSNotificiation and string

Question

I'm passing a string in one class to a UILabel in my view controller class. For some reason the string isn't being passed. when I check whats in the string it is 0x0

class.m

[[NSNotificationCenter defaultCenter] postNotificationName:@"notification"
                                                    object:self];

somestring = @"...";

ViewController.m

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(handleData:)
                                             name:@"notification"
                                           object:nil];

}
- (void)handleData:(NSNotification *)notification {


[[NSOperationQueue mainQueue] addOperationWithBlock:^{

    self.timerLabel.text =somestring;

}];
}

libc++abi.dylib: terminating with uncaught exception of type NSException - breakpoint at label.text = class.somestring — user3219182, Apr 01 '14 at 09:21
the label is connected in a storyboard and in . h: @property(nonatomic,strong) IBOutlet UILabel *label; — user3219182, Apr 01 '14 at 09:26
but you have mention your label name "lableinthisclass" in your code? Please cross check — kb920, Apr 01 '14 at 09:29
I thought the label is initialised from the storyboard connection? — user3219182, Apr 01 '14 at 09:32
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[class copyWithZone:]: unrecognized selector sent to instance 0x8c4c7e0' — user3219182, Apr 01 '14 at 09:33
notification.object not having string value Print value in nslog — kb920, Apr 01 '14 at 09:36
Please try the following: lableinthisclass.text = self.class.somestring.description; I think the passed object is no NSString, but rather an NSDictionairy — Lepidopteron, Apr 01 '14 at 09:37
http://stackoverflow.com/questions/10784207/uilabel-copywithzone-unrecognized-selector-sent-to-instance Might be help you — kb920, Apr 01 '14 at 09:43

score 1 · Answer 1 · answered Apr 01 '14 at 09:34

1

You look to have a few issues:

I'm not sure why you are using class in self.class.somestring, I would expect it just to be self.somestring. If you have added a class method then the naming and intention is poor.

The notification object is a controller instance, so, using self.class.somestring = notification.object; will store that controller instance. Not a string. So, when you later do lableinthisclass.text = self.class.somestring; you are treating the controller instance as a string and getting an exception.

Consider whether the class interaction is correct and use a string where your code expects a string.

answered Apr 01 '14 at 09:34

Wain

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Okay thanks. removing the notification object stopped the exception. – user3219182 Apr 01 '14 at 09:39
I've updated the code to show even when I assign the string to the text it's not updating. Thanks. – user3219182 Apr 01 '14 at 13:46
`the string it is 0x0` => this means the string is `nil` and thus contains nothing... – Wain Apr 01 '14 at 14:23

NSNotificiation and string

1 Answers1