title: How to Show/Hide content of UICollectionView
body: <p>I have 8 product fill to UICollection View, but i just want show 4 product. When user click button "See more", interface will dropdown and show remain content. But i have no ideas about how to make this. My initial solution is i divided UICollectionView to 2 part, part one will show 4 product, part two will hidden and when i click button "see more" it will show them. But problem is : when part two hidden,postion of part two still here, i want position of button "see more" and all content below will content will be put up.</p>
  
  <pre><code>    if(collectionViewDM.hidden == true){
          collectionViewDM.hidden = false
      }
      else{
          collectionViewDM.hidden = true
      }      
  }
  </code></pre>
  
  <p>Please help me, i'm beginner and i have no ideas about solution for problem</p>