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)
}
解决方法
看起来正确的方法签名是：
func controller(controller: NSFetchedResultsController,didChangeObject anObject: AnyObject,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方法的签名.为此,您只需在定义方法时键入controller以查看匹配的所有方法的列表.