ios - Objective-C 方法' Controller :didChangeObject:atIndexPath:forChangeType:newIndexPath

Question

Objective-C method 'controller:didChangeObject:atIndexPath:forChangeType:newIndexPath:' provided by method 'controller(:didChangeObject:atIndexPath:forChangeType:newIndexPath:)' conflicts with optional requirement method 'controller(:didChangeObject:atIndexPath:forChangeType:newIndexPath:)' in protocol 'NSFetchedResultsControllerDelegate'

func controller(controller: NSFetchedResultsController, didChangeObject anObject: NSManagedObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
    if self.collectionView?.window == nil {
        return
    }

    let change = NSMutableDictionary()

    switch(type)
    {
    case .Insert:
        change[NSNumber(unsignedLong:type.rawValue)] = newIndexPath
    case .Delete:
        change[NSNumber(unsignedLong:type.rawValue)] = indexPath
    case .Update:
        change[NSNumber(unsignedLong:type.rawValue)] = indexPath
    case .Move:
        change[NSNumber(unsignedLong:type.rawValue)] = NSArray(objects: indexPath!, newIndexPath!)
    default:
        break
    }
    self.objectChanges?.addObject(change)
}

Answer 1

看起来正确的方法签名是:

func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {

}

解决这些问题的任何简单方法是允许 Xcode 自动完成方法签名。然后，用自动生成的签名替换您的方法的签名。为此，您只需在定义方法时键入 controller 即可查看所有匹配方法的列表。