Error when declaring NSManagedObjectContext

问题

I'm trying to create a NSManagedObjectContext object. They error reads as follows:

Expected specifier-qualifier-list before 'NSManagedObjectContext'

and here is my header file:

#import <UIKit/UIKit.h>


@interface FavouritesViewController : UITableViewController {
  NSArray *favourites;
  NSManagedObjectContext *context;
}

@property (nonatomic, retain) NSArray *favourites;
@property (nonatomic, retain) NSManagedObjectContext *context;

@end

Anyone know I might be missing here?

回答1:

Most probably you have forgotten to include the CoreData header in your file. Right after the line #import <UIKit/UIKit.h> you need another line that reads #import <CoreData/CoreData.h>. After this the file should compile fine. Also make sure that you have CoreData in your linked libraries, otherwise you will get runtime errors.

回答2:

You need to add @class NSManagedObject above your interface directive. This will tell the compiler that NSManagedObject is a real class. You then need to have #import <CoreData/CoreData.h> in your .m file.

来源：https://stackoverflow.com/questions/4101384/error-when-declaring-nsmanagedobjectcontext