copywithzone

When implementing this method of NSCopying in a class to enable copy, what is the zone param use ? If I set a new object, I do not need to alloc it with allocWithZone as an alloc is just enough... I'm confused... Lily Ballard It's a relic from the old days, where we had multiple "zones" to allocate in. These days, all apps only have a single zone where all allocations are made, but the NSZone class still exists and far too much code is written to depend on +allocWithZone: being the fundamental allocation method to make the change. In short, you can ignore the NSZone struct in its entirety, and

I have a custom class Thing:NSManagedObject with an attribute of adminName. I am trying to create a copyWithZone function in this Thing class, but when I run the app it says setAdminName doesn't exist. In my implementation file I am using @dynamic adminName; -(id) copyWithZone: (NSZone *) zone { Thing *regCopy = [[Thing allocWithZone: zone] init]; regCopy.attendeeNum = [self adminName]; return regCopy; } I don't believe I can just change @dynamic to @synthesize since I am using Core Data. NSManagedObject does not conform to the NSCopying protocol. If you want to create a new record with the

I feel like I'm banging my head against the wall here (and I'm ready to do that, frankly). I'm trying to set a background to the view. Background I need to set is an image and I'm using this code (which works perfectly fine in two other UIViewController subclasses - this was a copy/paste into the new file): UIImage *img = [gameNode imageFromKey:@"background"]; UIColor *bg = [[UIColor alloc] initWithPatternImage:img]; self.view.backgroundColor = bg; [bg release]; As I said, this works perfectly fine in two other places, however here, line self.view.backgroundColor = bg throws

I am trying to clear up a few things in my head about implementing copyWithZone: , can anyone comment on the following ... // 001: Crime is a subclass of NSObject. - (id)copyWithZone:(NSZone *)zone { Crime *newCrime = [[[self class] allocWithZone:zone] init]; if(newCrime) { [newCrime setMonth:[self month]]; [newCrime setCategory:[self category]]; [newCrime setCoordinate:[self coordinate]]; [newCrime setLocationName:[self locationName]]; [newCrime setTitle:[self title]]; [newCrime setSubtitle:[self subtitle]]; } return newCrime; } // 002: Crime is not a subclass of NSObject. - (id)copyWithZone: