title: Dynamically adding content to UICollectionView
body: <p>I have a UICollectionView that is backed by a web service. I initially load 100 items from the service into the collection view. When the user reaches the bottom of the view, I dyanmically load the next "page" of content.</p>
  
  <p>This is working, but my collectionView flashes and re-draws the entire view from the top. I am trying to get it to just begin drawing the new content at the bottom of the view.</p>
  
  <p>Code for adding new content to the collectionview:</p>
  
  <pre><code>- (void)insertIntoCollectionView: (int) itemCnt {
  
  // only do the batchupdate for NON-initial load
  
  if(curPage != 0) {
  // Add items to main photos array, and update collectionview using batchUpdate
      [self.collectionView performBatchUpdates:^{
  
      // Get starting size before update
      int resultsSize = itemCnt;
  
      // Create a new array to hold the indexpath for the inserted data
      NSMutableArray *arrayWithIndexPaths = [NSMutableArray array];
  
      // Add indexpath objects to the new array to be added to the collection view
      for (int i = resultsSize; i &lt; resultsSize + itemCnt; i++) {
          [arrayWithIndexPaths addObject:[NSIndexPath indexPathForRow:i inSection:0]];
      }
      // Update the collectionview
      [self.collectionView insertItemsAtIndexPaths:arrayWithIndexPaths];
  }
      completion:nil];
  } else {
      [self.collectionView reloadData];
  }
  curPage++;
  </code></pre>
  
  <p>Anything obvious? It functionally works, but looks pretty bad with all of the flashing and re-drawing.</p>