image - 如何确定 PFFile 是 Video 还是 Image？

Question

我正在使用 Parse 在 IO 中创建一个应用程序，并且想知道如何确定我得到的文件是视频还是图像？有什么建议吗？

Answer 1

这是我到目前为止所得到的

      if let value = allPost[indexPath.row]["imageFile"] as? PFFile {

        let PFFileURLFromParse = value.url

        let fileUrl = NSURL(string: PFFileURLFromParse!)

      func thumbnailImagePreview() -> UIImage?

        {

            let asset = AVURLAsset(URL: fileUrl!)

            let imageGenerator = AVAssetImageGenerator(asset: asset)

            imageGenerator.appliesPreferredTrackTransform = true

            imageGenerator.apertureMode = AVAssetImageGeneratorApertureModeEncodedPixels

            do {

                let time: CMTime = CMTime(seconds: 0.0, preferredTimescale:1)

                let imageRef = try imageGenerator.copyCGImageAtTime(time, actualTime: nil)

                return UIImage(CGImage: imageRef)

            } catch {

                return nil

            }

        }

       if (fileUrl!.pathExtension!.lowercaseString == "mov"){

            print("Parse image is a mov: \(fileUrl!.pathExtension!.lowercaseString)”);

fileExtenion = "mov";

cell.ImagePost.image = thumbnailImagePreview()

            cell.ImagePost.loadInBackground()

            print("fileExtenion is \(fileExtenion)")

         }

        else{

            fileExtenion = ".png";

            print("DEFAULTING TO file type, Parse image is a png: \(fileUrl!.pathExtension!.lowercaseString)");

        }

        cell.ImagePost.file = value

        cell.ImagePost.loadInBackground()

    }

// 但是单元格的加载时间太长了我如何把它放在 collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {}