instance variables not accessible - iphone

Question

Serious Problem here... i'm getting ECX_BAD_ACCESS if i try to NSLog an instance variable of my custom object. Following Function is called in my ViewController, payload holds String Data which is pulled from a url.
- (void) initVcardWithData:(NSString *)payload {
NSLog(#"1. initVcardWithData");
aVCard = [[vcardItem alloc] initWithPayload:payload];
VCardViewController *aVCardViewController = [[VCardViewController alloc] initWithVCard:aVCard];
[self presentModalViewController:aVCardViewController animated:YES];
[aVCard release];
}
So far so good. The initWithWithVCard function is as follows, theVCard and theVCardN are defined in #implementation and also set as a #property (nonatomic, retain) in (.h).:
-(id)initWithVCard:(vcardItem *)aVCard {
if(self = [super init]) {
theVCard = [aVCard retain];
theVCardN = [theVCard.PersonName retain];
}
NSLog(#"---- vCardViewController :: initWithVcard :: FirstName: %#", theVCard.PersonName.FirstName);
return self;
}
If i access the theVCardN object in my ViewController aVCardViewController within ViewDidLoad everything works like a charm. I set some labels with data from that object.
If i then try to access the instance variables from theVCardN within a function which is called from an IBAction which is connected to a button in View, i get an EXC_BAD_ACCESS error at the debugger console. The Function which tries to pull data from the instance variables is as follows:
-(IBAction)addressbookButtonTapped {
NSLog(#"RETAIN COUNT FOR theVCard: %i", [theVCard retainCount]);
NSLog(#"RETAIN COUNT FOR theVCardN: %i", [theVCardN retainCount]);
NSLog(#"Save to Adressbook: %#", theVCardN.FirstName);
//[self dismissModalViewControllerAnimated:YES];
}
The RetainCounter for theVCardN right before calling NSLog outputs "1". The NSLog Line then returns EXC_BAD_ACCESS in Debugger Console.
Any idea ?

Answer 1

Do not call -retainCount. Absolute retain counts are useless.
retainCount returns the absolute retain count of an object. The actual value will be an implementation detail that is very often completely out of your control as the system frameworks may do any number of things internally to cause the retain count to be modified in ways you don't expect.
It is useless for debugging and their are a wealth of tools that are specifically focused on tracking down these kinds of issues.
First, if there is a crash, there is a backtrace. Post it. Probably not that interesting in this case, but, still, always look to the backtrace to at least confirm that it is crashing where/how you think it is.
From the evidence posted, it sounds like theVCardN.FirstName is either set to garbage or the underlying string has been over-released. Turn on zombie detection mode and see if that is the case. Since it is crashing on FirstName, then show the code related to creating/storing the FirstName.
Also, instance variables and methods should always start with a lowercase letter; PersonName should be personName & FirstName should be firstName.

Answer 2

Maybe i'm reading the code wrong or misunderstanding your class structure, but it looks like you logging:
NSLog(#"Save to Adressbook: %#", theVCardN.FirstName);
Above, where you say it is still working, you are logging:
theVCard.PersonName.FirstName
Are you missing the "PersonName"? Meaning you should be logging:
NSLog(#"Save to Adressbook: %#", theVCardN.PersonName.FirstName);