Duplicate symbol error when adding NSManagedObject subclass, duplicate link
If you do not generate managed object subclass automatically, then don’t forget to check “Codegen” settings for an Entity in Data Model Inspector:
objective-c-category
Protocol versus Category
A protocol is the same thing as an interface in Java: it’s essentially a contract that says, “Any class that implements this protocol will also implement these methods.” A category, on the other hand, just binds methods to a class. For example, in Cocoa, I can create a category for NSObject that will allow me … Read more
Add rounded corners to all UIImageViews
Check this – Rounded Corners on UIImage The layer modification seems to be the best way. UIImageView * roundedView = [[UIImageView alloc] initWithImage: [UIImage imageNamed:@”wood.jpg”]]; // Get the Layer of any view CALayer * l = [roundedView layer]; [l setMasksToBounds:YES]; [l setCornerRadius:10.0];
Class extension vs class category
The main difference is that with an extension, the compiler will expect you to implement the methods within your main @implementation, whereas with a category you have a separate @implementation block. So you should pretty much only use an extension at the top of your main .m file (the only place you should care about … Read more