iPhone - Crash using addObject on a NSMutableArray

Question

I have a problem here. Or Maybe I\'m really tired...

I have a class :

@interface THECLASS : UIViewController  {
    NSMuta         


        

Answer 1

For some reason you're calling the addObject: method on an instance of NSArray, as the stack trace indicates. Perhaps the synthesized getter of your param object returns an NSArray? Don't use the getter in your method:

- (void) changedSelectorValue:(NSIndexPath*)indexPath isOn:(BOOL)isOn {
    [param addObject:@"eeeee"];
}

Ultimately, the error is correct. You're calling a mutating method on an immutable object. Strange enough, in my testing this doesn't cause a compiler error or warning:

NSMutableArray *array = [[NSArray alloc] init];

Edit: Whether you want to believe it or not, somehow the param ivar is being set to an instance of an NSArray. Override the setter:

- (void)setParam:(NSMutableArray *)p {
    if (param != p) {
        [param release];
        param = [p retain];
    }
}

Then add a breakpoint on that method, and check to see when an NSArray is being passed in.