title: How could I set gradient fixed background on UICollectionView?
body: <p>I used following code. </p>
  
  <pre><code>CAGradientLayer* collectionRadient = [CAGradientLayer layer];
  collectionRadient.bounds = self.collectionView.bounds;
  collectionRadient.anchorPoint = CGPointZero;
  collectionRadient.colors = [NSArray arrayWithObjects:(id)[startColor CGColor],(id)[endColor CGColor], nil];
  [self.collectionView.layer insertSublayer:collectionRadient atIndex:0];
  </code></pre>
  
  <p>But it drawn on cells included images. so cell was not shown.</p>
  
  <p>I want to draw gradient background of UICollectionView under Cells and fixed it when view scrolled.
  Let me know Please.</p>