title: ios swift UICollectionVIew Issue: The behavior of the UICollectionViewFlowLayout is not defined because
body: <p>I am using UICollectionView using the flow layout. I have made a custom UICollectionView with horizontal. error-</p>
  
  <p>The behavior of the UICollectionViewFlowLayout is not defined because:
  the item height must be less than the height of the UICollectionView minus the section insets top and bottom values, minus the content insets top and bottom values.</p>
  
  <p>The relevant UICollectionViewFlowLayout instance is , and it is attached to ; layer = ; contentOffset: {-8, -8}; contentSize: {0, 100}> collection view layout: .
  2019-11-18 11:51:59.017124+0530 eVyapaar_Grocery[3964:1811183] Make a symbolic breakpoint at UICollectionViewFlowLayoutBreakForInvalidSizes to catch this in the debugger.</p>
  
  <pre><code>Here is my code:
  collectionView.delegate = self
  collectionView.dataSource = self
  collectionView.register(UINib(nibName: "cellID", bundle: nil), forCellWithReuseIdentifier:"cellID")
  collectionView.contentInset = UIEdgeInsets(top: 8, left: 8, bottom: 8, right: 8)
  collectionView.showsHorizontalScrollIndicator = false
  collectionView.isScrollEnabled = true
  if let layout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout {
         layout.scrollDirection = .horizontal
         collectionView!.collectionViewLayout = layout
  }
  
  extension ViewController: UICollectionViewDelegateFlowLayout {
      func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -&gt; CGSize {
          if collectionView == myCcollectionView {
              var width: CGFloat = 0
              if UIDevice.isIpad {
                  width = ((UIScreen.main.bounds.width/6)-6)
              } else {
                  width = ((UIScreen.main.bounds.width/3)-6)
              }
              return CGSize(width: width, height: width)
          } 
      }
  
      func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -&gt; CGFloat {
          return 1
  
      }
  
      func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -&gt; CGFloat {
          return 0
      }
  
      func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -&gt; UIEdgeInsets {
          return UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
      }
  }
  </code></pre>