在斯威夫特實施fetchedresultsviewcontroller 3

Question

我想在斯威夫特3實施fetchedresultsviewcontroller和控制器的委託屬性設置爲自當我遇到了以下錯誤：

無法指定類型的值「SomeRootViewController」鍵入 'NSFetchedResultsControllerDelegate？'

SomeRootViewController.swift

@available(iOS 10.0, *) 
@objc class SomeRootViewController: UIViewController, UITableViewDataSource, UITableViewDelegate { 

    var delegate: SomeRootViewControllerDelegate? 
    public var context: NSManagedObjectContext! 

    private let persistentContainer = NSPersistentContainer(name: "Accessory") 


    fileprivate lazy var fetchedResultsController: NSFetchedResultsController<Accessory> = { 
     // Create Fetch Request 
     let fetchRequest: NSFetchRequest<Accessory> = Accessory.fetchRequest() as! NSFetchRequest<Accessory> 

     // Configure Fetch Request 
     fetchRequest.sortDescriptors = [NSSortDescriptor(key: "AccessoryAttributes.name", ascending: true)] 

     // Create Fetched Results Controller 
     let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.persistentContainer.viewContext, sectionNameKeyPath: nil, cacheName: nil) 

     // Configure Fetched Results Controller 
     fetchedResultsController.delegate = self //<<-- this is where error occurs 

     return fetchedResultsController 
    }() 

有人可以解釋這個問題給我，我怎麼能解決這個問題？

Answer 1

因爲要設置委託給自己，你還需要做出SomeRootViewController符合NSFetchedResultsControllerDelegate協議，像這樣：

class SomeRootViewController: NSFetchedResultsControllerDelegate, UIViewController, UITableViewDataSource, UITableViewDelegate {