如何自动重新加载集合视图？

Question

我使用集合视图开发了一个RSS阅读器应用程序.我的问题是,在第一次启动时,应用程序出现空白.

过程是,RSS提要从Web中提取,存储到设备上的临时文件中,然后通过集合视图显示.

我的问题是如何在文件加载后让应用程序自动重新加载数据？这样用户就看不到初始的空白屏幕.

我试过添加这段代码

       [self.collection1 performBatchUpdates:^{
       [self.collection1 reloadSections:[NSIndexSet indexSetWithIndex:0]];
   } completion:nil];

但是它不适用于初始视图.

我应该从appdelegate做些什么吗？或者从集合视图控制器本身？

请指教

下面是用于获取和显示我的数据的代码....

#pragma mark - UICollectionViewDataSourceDelegate
- (NSInteger) numberOfSectionsInCollectionView:(UICollectionView *)collectionView
  {
  return 1;
  }

- (NSInteger) collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
 return [_articleListmain count];
}

- (UICollectionViewCell *) collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
 MainCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"articleCellmain"
                                                                           forIndexPath:indexPath];
NSDictionary *item = [_articleListmain objectAtIndex:indexPath.item];

// set the article image
[cell.image setImageWithURL:[item objectForKey:@"image"]];

// set the text of title UILabel
cell.title.text = [NSString stringWithFormat:@"%@\n\n\n\n", [item objectForKey:@"title"]];
cell.title.textColor = [UIColor colorWithRed:33.0f/255.0f green:74.0f/255.0f blue:146.0f/255.0f alpha:1.0f];

// set the text of summary UILabel
cell.description.text = [NSString stringWithFormat:@"%@\n\n\n\n\n\n\n\n\n", [item objectForKey:@"description"]];


cell.targetURL.text = [NSString stringWithFormat:@"%@\n\n\n\n", [item objectForKey:@"link"]];

cell.category.text = [NSString stringWithFormat:@"%@\n\n\n\n", [item objectForKey:@"category"]];

cell.date.text = [NSString stringWithFormat:@"%@\n\n\n\n", [item objectForKey:@"pubDate"]];

cell.image.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"placement.png"]];


return cell;


}

Answer 1

一旦知道下载已完成,您应该能够使用[collectionView reloadData].