也許你應該確認到NSFetchedResultsControllerDelegate
而且提供這樣的功能：
func controllerWillChangeContent(controller: NSFetchedResultsController) {
self.tableView.beginUpdates()
}
func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
switch type {
case .Insert:
self.tableView.insertSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
case .Delete:
self.tableView.deleteSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
default:
return
}
}
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
switch type {
case .Insert:
tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: .Fade)
case .Delete:
tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: .Fade)
case .Update:
self.configureCell(tableView.cellForRowAtIndexPath(indexPath!)!, withObject: anObject as! NSManagedObject)
case .Move:
tableView.moveRowAtIndexPath(indexPath!, toIndexPath: newIndexPath!)
}
}
func controllerDidChangeContent(controller: NSFetchedResultsController) {
self.tableView.endUpdates()
}
這裏是你可以比較蘋果主從模板中使用的示例代碼：
class MasterViewController: UITableViewController, NSFetchedResultsControllerDelegate {
var detailViewController: DetailViewController? = nil
var managedObjectContext: NSManagedObjectContext? = nil
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.navigationItem.leftBarButtonItem = self.editButtonItem()
let addButton = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: #selector(insertNewObject(_:)))
self.navigationItem.rightBarButtonItem = addButton
if let split = self.splitViewController {
let controllers = split.viewControllers
self.detailViewController = (controllers[controllers.count-1] as! UINavigationController).topViewController as? DetailViewController
}
}
override func viewWillAppear(animated: Bool) {
self.clearsSelectionOnViewWillAppear = self.splitViewController!.collapsed
super.viewWillAppear(animated)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func insertNewObject(sender: AnyObject) {
let context = self.fetchedResultsController.managedObjectContext
let entity = self.fetchedResultsController.fetchRequest.entity!
let newManagedObject = NSEntityDescription.insertNewObjectForEntityForName(entity.name!, inManagedObjectContext: context)
// If appropriate, configure the new managed object.
// Normally you should use accessor methods, but using KVC here avoids the need to add a custom class to the template.
newManagedObject.setValue(NSDate(), forKey: "timeStamp")
// Save the context.
do {
try context.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.
//print("Unresolved error \(error), \(error.userInfo)")
abort()
}
}
// MARK: - Segues
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "showDetail" {
if let indexPath = self.tableView.indexPathForSelectedRow {
let object = self.fetchedResultsController.objectAtIndexPath(indexPath)
let controller = (segue.destinationViewController as! UINavigationController).topViewController as! DetailViewController
controller.detailItem = object
controller.navigationItem.leftBarButtonItem = self.splitViewController?.displayModeButtonItem()
controller.navigationItem.leftItemsSupplementBackButton = true
}
}
}
// MARK: - Table View
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return self.fetchedResultsController.sections?.count ?? 0
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
let sectionInfo = self.fetchedResultsController.sections![section]
return sectionInfo.numberOfObjects
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)
let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as! NSManagedObject
self.configureCell(cell, withObject: object)
return cell
}
override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
if editingStyle == .Delete {
let context = self.fetchedResultsController.managedObjectContext
context.deleteObject(self.fetchedResultsController.objectAtIndexPath(indexPath) as! NSManagedObject)
do {
try context.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.
//print("Unresolved error \(error), \(error.userInfo)")
abort()
}
}
}
func configureCell(cell: UITableViewCell, withObject object: NSManagedObject) {
cell.textLabel!.text = object.valueForKey("timeStamp")!.description
}
// MARK: - Fetched results controller
var fetchedResultsController: NSFetchedResultsController {
if _fetchedResultsController != nil {
return _fetchedResultsController!
}
let fetchRequest = NSFetchRequest()
// Edit the entity name as appropriate.
let entity = NSEntityDescription.entityForName("Event", inManagedObjectContext: self.managedObjectContext!)
fetchRequest.entity = entity
// Set the batch size to a suitable number.
fetchRequest.fetchBatchSize = 20
// Edit the sort key as appropriate.
let sortDescriptor = NSSortDescriptor(key: "timeStamp", ascending: false)
fetchRequest.sortDescriptors = [sortDescriptor]
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
let aFetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.managedObjectContext!, sectionNameKeyPath: nil, cacheName: "Master")
aFetchedResultsController.delegate = self
_fetchedResultsController = aFetchedResultsController
do {
try _fetchedResultsController!.performFetch()
} 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.
//print("Unresolved error \(error), \(error.userInfo)")
abort()
}
return _fetchedResultsController!
}
var _fetchedResultsController: NSFetchedResultsController? = nil
func controllerWillChangeContent(controller: NSFetchedResultsController) {
self.tableView.beginUpdates()
}
func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
switch type {
case .Insert:
self.tableView.insertSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
case .Delete:
self.tableView.deleteSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
default:
return
}
}
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
switch type {
case .Insert:
tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: .Fade)
case .Delete:
tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: .Fade)
case .Update:
self.configureCell(tableView.cellForRowAtIndexPath(indexPath!)!, withObject: anObject as! NSManagedObject)
case .Move:
tableView.moveRowAtIndexPath(indexPath!, toIndexPath: newIndexPath!)
}
}
func controllerDidChangeContent(controller: NSFetchedResultsController) {
self.tableView.endUpdates()
}
/*
// Implementing the above methods to update the table view in response to individual changes may have performance implications if a large number of changes are made simultaneously. If this proves to be an issue, you can instead just implement controllerDidChangeContent: which notifies the delegate that all section and object changes have been processed.
func controllerDidChangeContent(controller: NSFetchedResultsController) {
// In the simplest, most efficient, case, reload the table view.
self.tableView.reloadData()
}
*/
}