Ios 如何获取摄像机卷中所有视频文件的url？

我正在使用以下代码在摄影机滚动中显示所有视频，并在UICollectionView中显示它们

func getVideoFromCameraRoll() {
    let options = PHFetchOptions()
    options.sortDescriptors = [ NSSortDescriptor(key: "creationDate", ascending: false) ]
    options.predicate = NSPredicate(format: "mediaType = %d", PHAssetMediaType.video.rawValue)
    videos = PHAsset.fetchAssets(with: options)
    videoLibraryCV.reloadData()
}

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return videos.count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath)
    let asset = videos!.object(at: indexPath.row)
    let width: CGFloat = 150
    let height: CGFloat = 150
    let size = CGSize(width:width, height:height)
    cell.layer.borderWidth = 0.5
    cell.layer.borderColor = UIColor.lightGray.cgColor
    PHImageManager.default().requestImage(for: asset, targetSize: size, contentMode: PHImageContentMode.aspectFit, options: nil)
    {   (image, userInfo) -> Void in

        let imageView = cell.viewWithTag(1) as! UIImageView
        imageView.image = image

        let labelView = cell.viewWithTag(2) as! UILabel
        labelView.text = String(format: "%02d:%02d",Int((asset.duration / 60)),Int(asset.duration) % 60)
    }
    return cell
}

---

现在我需要播放UICollectionView中选定的视频。如何获取所选视频URL？

用于在

didSelectItemAtIndexPath

方法上播放视频

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
 let asset = photos!.object(at: indexPath.row)
 guard(asset.mediaType == PHAssetMediaType.Video)
 else {
  print("Not a valid video media type")
  return
 }

 PHCachingImageManager().requestAVAssetForVideo(asset, options: nil, resultHandler: {
  (asset: AVAsset ? , audioMix : AVAudioMix ? , info : [NSObject: AnyObject] ? ) in
  let asset = asset as!AVURLAsset
  print(asset.URL) // Here is video URL
 })

}