core-data

问题 Like many iOS developers, I use CoreData, and like many iOS developers that use CoreData, I have hard-to-track-down thread violation errors. I'm trying to implement a debugging strategy for throwing exceptions when the CoreData concurrency rules are broken. My attempt is below - my question is, is this valid? Will it produce false positives? Summary: when an NSManagedObject is created, note the thread. Whenever a value is accessed later on, check if the current thread is the same as the

问题 I have been trying to figure out this problem for 2 days now. I keep getting an error when I try to save. //self.data is NSManagedObject. kAppDelegate.moc is the managed object context. self.data = [NSEntityDescription insertNewObjectForEntityForName:@"Data" inManagedObjectContext:kAppDelegate.moc]; [self.data setValue:[NSNumber numberWithBool:NO] forKey:@"isit"]; [self.data setValue:@"" forKey:@"name"]; NSError *error; if(![self.data.managedObjectContext save:&error]) { NSLog(@"Save did not

问题 I recently changed my developer account from company to individual. I have successfully transferred my applications, apart from the application groups. I cannot see anyway of transferring the existing app groups and my thoughts are that if I create a new app group, existing users will: Not be able to upgrade If they were able to upgrade, their existing data would be lost None of these situations look good unfortunately. Therefore in terms of TL;DR: How can I transfer app groups between

问题 I'm using Apple's concurrency core data debugger. -com.apple.CoreData.ConcurrencyDebug 1 From time to time I got __Multithreading_Violation_AllThatIsLeftToUsIsHonor__ , even I'm almost sure threading is not violated. This is part of code where exception occurs (code is part of protocol that extends NSManagedObject): public static func find(arrayBy predicate: NSPredicate, sort: [NSSortDescriptor] = [], limit: Int? = nil) -> [Self] { let fetchRequest = NSFetchRequest<Self>(entityName: "\(Self

问题 I'm having a problem saving things in the background. So I have 2 operations that I chain with RxSwift. The first items are saved and when I fetch them on a main context all the information is there. But in the second operation I fetch the same object and I update it with more information. Now whatever I do there it never updates the entity. This is my coredata code: class CoreDataStack { static let modelName = "Mo_Application" static let model: NSManagedObjectModel = { let modelURL = Bundle

问题 I'm having a problem saving things in the background. So I have 2 operations that I chain with RxSwift. The first items are saved and when I fetch them on a main context all the information is there. But in the second operation I fetch the same object and I update it with more information. Now whatever I do there it never updates the entity. This is my coredata code: class CoreDataStack { static let modelName = "Mo_Application" static let model: NSManagedObjectModel = { let modelURL = Bundle

问题 In Apple-generated code (Core Data NSManagedObject subclasses, for example) I see this: @objc(LPFile) public class LPFile: NSManagedObject { ... } My question is: why is the @objc declaration done as above, instead of: @objc public class LPFile: NSManagedObject { ... } or @objcMembers public class LPFile: NSManagedObject { ... } What is special about the separate @objc(identifier) declaration? I can't seem to find documentation about it and googling just turns up the other two approaches.

问题 In Apple-generated code (Core Data NSManagedObject subclasses, for example) I see this: @objc(LPFile) public class LPFile: NSManagedObject { ... } My question is: why is the @objc declaration done as above, instead of: @objc public class LPFile: NSManagedObject { ... } or @objcMembers public class LPFile: NSManagedObject { ... } What is special about the separate @objc(identifier) declaration? I can't seem to find documentation about it and googling just turns up the other two approaches.

问题 In Apple-generated code (Core Data NSManagedObject subclasses, for example) I see this: @objc(LPFile) public class LPFile: NSManagedObject { ... } My question is: why is the @objc declaration done as above, instead of: @objc public class LPFile: NSManagedObject { ... } or @objcMembers public class LPFile: NSManagedObject { ... } What is special about the separate @objc(identifier) declaration? I can't seem to find documentation about it and googling just turns up the other two approaches.

问题 The code is let request: NSFetchRequest<NSFetchRequestResult> = Item.fetchRequest() print(request) Item is an entity of Core Data. The first execution is correct, but when execute it again error occurs Thread 12: EXC_BAD_ACCESS (code=1, address=0x0) . The following is logs: This is a similar question, but with Object C. It says that defining managedObjectContext in view controller directly instead of transferring it from AppDelegate can fix the bug. In my code, the managedObjectContext is in