在UICollectionViewCell中处理滚动视图大小

我做了一个水平UICollectionView,内部UICollectionViewCell我有scrollview和在scrollview内我有一个imageView.

我遇到的问题是,当我放大imageView时,scrollView会占用所有单元格大小,因此它不适合图像大小的高度和宽度.通过向上和向下滚动图像从scrollview中消失,我有不知道我的代码中出了什么问题.

我的ColectionViewCell代码:

class CollectionViewCell: UICollectionViewCell {
    @IBOutlet var scrollView: UIScrollView!
    @IBOutlet var ImageV: UIImageView!
}

CollectionView代码:

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
  let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! CollectionViewCell

  cell.scrollView.contentMode = UIViewContentMode.ScaleAspectFit
  cell.scrollView.delegate = self
  cell.ImageV.image = UIImage(named: array[indexPath.row])
  cell.ImageV.contentMode = UIViewContentMode.ScaleAspectFit

  cell.scrollView.minimumZoomScale = 1
  cell.scrollView.maximumZoomScale = 4;
  cell.scrollView.contentSize = cell.ImageV.frame.size

  return cell
}

func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {

  return CGSize(width: self.collectionView.frame.size.width , height: self.collectionView.frame.size.height - 100)

}

func viewForZoomingInScrollView(scrollView: UIScrollView) -> UIView? {

  let indexPath = NSIndexPath(forItem: Int(currentIndex), inSection: 0)

  if let cell1 = self.collectionView.cellForItemAtIndexPath(indexPath) {  
    let cell = cell1 as! CollectionViewCell
    let boundsSize = cell.scrollView.bounds.size
    var contentsFrame = cell.ImageV.frame

    if contentsFrame.size.width < boundsSize.width{
      contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2
    }else{
      contentsFrame.origin.x = 0
    }

    if contentsFrame.size.height < boundsSize.height {
      contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2
    }else{
      contentsFrame.origin.y = 0
    }
    return cell.ImageV    
  }      
   return UIView()     
 }


func scrollViewDidEndDecelerating(scrollView: UIScrollView) {

  currentIndex = self.collectionView.contentOffset.x / self.collectionView.frame.size.width;
  oldcell = currentIndex - 1

  let indexPath = NSIndexPath(forItem: Int(oldcell), inSection: 0)
  if let cell1 = self.collectionView.cellForItemAtIndexPath(indexPath) {
    let cell = cell1 as! CollectionViewCell
    cell.scrollView.zoomScale = 0 
  }
}

图片预览: https ://i.imgur.com/Gr2p09A.gifv

我的项目在此处找到: https ://drive.google.com/file/d/0B32ROW7V8Fj4RVZfVGliXzJseGM/view?usp=sharing