我的收藏视图更新需要帮助， 我有一个自定义布局的集合视图，我从ray wenderlich tutorial和NSFetchedResultsController
实现这是我更新集合视图的代码：
但该集合不会显示新的更新项目（正常布局都可以正常工作）
func controllerWillChangeContent(controller: NSFetchedResultsController) {
blockOperations = []
}
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
weak var collection = self.collectionView
switch type {
case .Insert:
guard indexPath != newIndexPath else { return }
blockOperations.append(
NSBlockOperation(block: { [weak collection] in
collection?.insertItemsAtIndexPaths([newIndexPath!])
})
)
case .Update:
guard indexPath != nil else { return }
blockOperations.append(
NSBlockOperation(block: { [weak collection] in
collection?.reloadItemsAtIndexPaths([indexPath!])
})
)
case .Move:
guard newIndexPath != nil else { return }
blockOperations.append(
NSBlockOperation(block: { [weak collection] in
collection?.moveItemAtIndexPath(indexPath!, toIndexPath: newIndexPath!)
})
)
case .Delete:
guard indexPath != nil else { return }
blockOperations.append(
NSBlockOperation(block: { [weak collection] in
collection?.deleteItemsAtIndexPaths([indexPath!])
})
)
}
}
func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
weak var collection = self.collectionView
switch type {
case .Insert:
blockOperations.append(
NSBlockOperation(block: { [weak collection] in
collection?.insertSections(NSIndexSet(index: sectionIndex))
})
)
case .Update:
blockOperations.append(
NSBlockOperation(block: { [weak collection] in
collection?.reloadSections(NSIndexSet(index: sectionIndex))
})
)
case .Delete:
blockOperations.append(
NSBlockOperation(block: { [weak collection] in
collection?.deleteSections(NSIndexSet(index: sectionIndex))
})
)
case .Move:
break
}
}
func controllerDidChangeContent(controller: NSFetchedResultsController) {
collectionView?.performBatchUpdates({ () -> Void in
for operation: NSBlockOperation in self.blockOperations {
operation.start()
}
}, completion: { (finished) -> Void in
if finished{
self.blockOperations.removeAll(keepCapacity: false)
}
})
}