objective-c - 由 NSFetchedResultsController 支持的 AQGridView

Question

我正在尝试实现一个使用获取结果 Controller 作为其数据源的 AQGridView。

我不是特别确定如何使用 GridView 处理 NSFetchedResultsController 委托(delegate)方法；即内容变化的。我了解如何将 FRC 用于其他 GridView 数据源委托(delegate)。

有人能给我指出正确的方向吗？

Answer 1

结果应该看起来像这样:

- (void)controllerWillChangeContent:(NSFetchedResultsController *)controller
{
  [gridView beginUpdates];
}

- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
       atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
  switch(type)
  {
    case NSFetchedResultsChangeInsert:
      break; 
    case NSFetchedResultsChangeDelete:
      break;
  }
}

- (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject
   atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type
  newIndexPath:(NSIndexPath *)newIndexPath
{

  ChannelPageViewController *currentPageController, *destinationPageController;

  NSIndexSet * indices = [[NSIndexSet alloc] initWithIndex: indexPath.row];
  NSIndexSet *newIndices = [[NSIndexSet alloc] initWithIndex:newIndexPath.row];

  switch(type) {
      case NSFetchedResultsChangeInsert:
        [gridView insertItemsAtIndices:newIndices withAnimation:AQGridViewItemAnimationNone];
      break;

      case NSFetchedResultsChangeDelete:
        [gridView deleteItemsAtIndices:indices withAnimation:AQGridViewItemAnimationNone];
        break;

      case NSFetchedResultsChangeUpdate:
        [gridView reloadItemsAtIndices:indices withAnimation:AQGridViewItemAnimationNone];
        break;

      case NSFetchedResultsChangeMove:
        [gridView deleteItemsAtIndices:indices withAnimation:AQGridViewItemAnimationNone];
        [gridView insertItemsAtIndices:newIndices withAnimation:AQGridViewItemAnimationNone];
        break;
   }
}

- (void)controllerDidChangeContent:(NSFetchedResultsController *)controller
{
  [gridView endUpdates];
  if ([[frc fetchedObjects] count] == 1) {
    [gridView reloadData];
  }

}