title: UICollectionView Reloading Data
body: <p>A question regarding reloading data in your <code>UICollectionView</code>.</p>
  
  <p>When using <code>reloadData</code> it only does this once any scrolling has finished. Then there is a small pause where the collection view freezes and cannot be interacted with until the new data is loaded in. How can I get around this?</p>
  
  <p>For example, I would have a view comprised of maybe 10/20/30 items, each with an image and label. I then update my dictionary with new images and strings and then reload the view to add these new items.</p>
  
  <p>Many thanks.</p>
  
  <p><strong>EDIT</strong>:</p>
  
  <p>On closer inspection, its not the reloading that causes the pause, its some other code, where I fetch some data. Why might this freeze my view though when i am not even reloading it to make changes to it?</p>
  
  <p>I am fetching this data from <code>-(void)scrollViewDidScroll:(UIScrollView *)scrollView</code></p>
  
  <p>EDIT 2:</p>
  
  <p>Ok here is some basic code</p>
  
  <pre><code>dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
      [self myMethodWithCompletionBlock:^(NSMutableDictionary *results, NSString *nextPageToken) {
          //No code in completion block is ever called when the method is called in the dispatch block! Regardless of what it is.
      }
  });
  </code></pre>