如何在coredata和xcode中插入多个/连续的新行？-(void)LoadDB{CoreDataAppDelegate*appdelegate=[[UIApplicationsharedApplication]delegate];context=[appdelegatemanagedObjectContext];NSManagedObject*newPref;newPref=[NSEntityDescriptioninsertNewObjectForEntityForName:NSStringFromClass([Preferenceclass])inManagedObjectC