Question

So my goal is to deliver a notification to another class with using NSNotificationCenter, I also want to pass object with the notification to the other class, how should I do this?

Answer 1

You must first register a notification name

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(startLocating:) name:@"ForceUpdateLocation" object:nil]; // don't forget the ":"

And then post a notification with a dictionary of parameters

[[NSNotificationCenter defaultCenter] postNotificationName:@"ForceUpdateLocation" object:self userInfo:[NSDictionary dictionaryWithObject:@"1,2,3,4,5" forKey:@"categories_ids"]]; 

and the method will be

- (void)startLocating:(NSNotification *)notification {

    NSDictionary *dict = [notification userInfo];
}