>我在保存核心数据时随机收到此错误
Unresolved error Error Domain=NSCocoaErrorDomain Code=132001 "(null)" UserInfo={message=attempt to recursively call -save: on the context aborted, stack trace=(
过去 3 个月一切正常，但最近由于应用程序的变化，我不得不调用很多获取和保存请求，其中一些处于循环中，有些在进行这些更改后关闭，我遇到了此错误。
这是核心数据管理器的代码
import Foundation
import CoreData
class CoreDataStack {
private init() {
}
class func getContext () -> NSManagedObjectContext {
return CoreDataStack.managedObjectContext
}
// MARK: - Core Data stack
static var managedObjectContext: NSManagedObjectContext = {
var applicationDocumentsDirectory: URL = {
// The directory the application uses to store the Core Data store file. This code uses a directory named "com.cadiridris.coreDataTemplate" in the application's documents Application Support directory.
let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
return urls[urls.count-1]
}()
var managedObjectModel: NSManagedObjectModel = {
// The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
let modelURL = Bundle.main.url(forResource: "Thyssenkrupp", withExtension: "momd")!
return NSManagedObjectModel(contentsOf: modelURL)!
}()
var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
// The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
// Create the coordinator and store
let coordinator = NSPersistentStoreCoordinator(managedObjectModel: managedObjectModel)
let url = applicationDocumentsDirectory.appendingPathComponent("Thyssenkrupp.sqlite")
var failureReason = "There was an error creating or loading the application's saved data."
let options = [ NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption:true ]
do {
try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: options)
} catch {
// Report any error we got.
var dict = [String: AnyObject]()
dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data" as AnyObject?
dict[NSLocalizedFailureReasonErrorKey] = failureReason as AnyObject?
dict[NSUnderlyingErrorKey] = error as NSError
let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
// Replace this with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
print("Unresolved error (wrappedError), (wrappedError.userInfo)")
//abort()
}
return coordinator
}()
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
let coordinator = persistentStoreCoordinator
var managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = coordinator
return managedObjectContext
}()
// MARK: - Core Data Saving support
class func saveContext () {
DispatchQueue.main.async {
if managedObjectContext.hasChanges {
do {
try managedObjectContext.save()
} catch {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
let nserror = error as NSError
print("Unresolved error (nserror), (nserror.userInfo)")
//abort()
}
}
}
}
}
请提供任何建议，为什么会出现此错误
问题是经常将数据保存到 CoreData，是的，您可以根据需要频繁地使用 CoreData，但如果添加/删除/更新数据并将其保存在循环中，它将在控制台上通过此错误这样做会导致此错误，并非总是如此，但最好在循环完成后保存 CoreData。由于在我们执行创建，更新，删除操作并且由于某种原因没有保存CoreData应用程序崩溃/关闭的情况下，保存到核心数据很重要，因此数据将从我们上次保存CoreData时丢失。保存到 CoreData 就像一个检查点，一切都被保存了。因此，循环保存不是有效的方法。