Question

嗨我得到了一个错误（FetchedResultsController.getter）。（闭包＃1）

错误点是

let fetchedResultsController =
    NSFetchedResultsController(fetchRequest: fetchRequest,
          managedObjectContext: self.managedObjectContext,
          sectionNameKeyPath: nil, cacheName: nil)

我删除了sql文件，并恢复了模拟器，但没有。我创建了sql文件但是当行执行时我就有了这个错误

这是我到目前为止的代码

var managedObjectContext : NSManagedObjectContext!

lazy var fetchedResultsController : NSFetchedResultsController<WeatherLocation> = {

    let fetchRequest = NSFetchRequest<WeatherLocation>()
    let entity = WeatherLocation.entity()
    fetchRequest.entity = entity

    fetchRequest.fetchBatchSize = 20

    let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.managedObjectContext, sectionNameKeyPath: nil, cacheName: nil)

    fetchedResultsController.delegate = self
    return fetchedResultsController
}()


override func viewDidLoad() {
    super.viewDidLoad()


    performFetch()

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func performFetch(){
    do{
        try fetchedResultsController.performFetch()
    }catch{
        fatalError("FatalError : \(error)")
    }
}

deinit {
    fetchedResultsController.delegate = nil
}

扩展名----

extension PlacesTableViewController : NSFetchedResultsControllerDelegate {

    func controllerWillChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
        print("***--- controllerWillChangeContent")
        tableView.beginUpdates()
    }

    func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {

        switch type {

        case .insert :
            print("***--- NSFetchedResultsChangeinsert (object)")
            tableView.insertRows(at: [indexPath!], with: .fade)

        case.delete:
            print("***--- NSFetchedResultsChangeDelete (object)")
            tableView.deleteRows(at: [indexPath!], with: .fade)

        case .update :
            print("***--- NSFetchedResultsChangeUpdate (object)")
            if let cell = tableView.cellForRow(at: indexPath!) {
                let weatherLocation = controller.object(at: indexPath!) as! WeatherLocation
                cell.textLabel?.text = weatherLocation.name
                cell.detailTextLabel?.text =  "Latitude:\(weatherLocation.latitude) , Longitude : \(weatherLocation.longitude)"
            }

        case .move:
            print("***--- NSFetchedResultsChangeMove (object)")
            tableView.deleteRows(at: [indexPath!], with: .fade)
            tableView.insertRows(at: [indexPath!], with: .fade)

        }

    }

    func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange sectionInfo: NSFetchedResultsSectionInfo, atSectionIndex sectionIndex: Int, for type: NSFetchedResultsChangeType) {

        switch type {
        case .insert :
            print("***--- NSFetchedResultsChangeInsert (section)")
            tableView.insertSections(IndexSet(integer: sectionIndex), with: .fade)
        case .delete :
            print("***--- NSFetchedResultsChangeDelete (section)")
            tableView.deleteSections(IndexSet(integer:sectionIndex), with: .fade)
        case .update :
            print("***--- NSFetchedResultsChangeUpdate")
        case.move:
            print("***--- NSFetchedResultsChangeMove")
        }

    }

    func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
        print("***--- controllerDidChangeContent")
        tableView.endUpdates()
    }

}

和AppDelegate.swift

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        let placesController = window?.rootViewController as! PlacesTableViewController
        placesController.managedObjectContext = managedObjectContext
        let _ = placesController.view
        print(applicationDocumentsDirectory)
        return true
    }

    lazy var persistentContainer : NSPersistentContainer = {
        let container = NSPersistentContainer(name: "DataModel")
        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error {
                fatalError("Could load data store : \(error)")
            }
        })
        return container
    }()

    lazy var managedObjectContext : NSManagedObjectContext = self.persistentContainer.viewContext

我知道为什么会收到此错误？

由于

CoreData错误：（FetchedResultsController.getter）。（闭包＃1）

0 个答案: