Ios 从文档中的视频获取缩略图时出现问题

我试图从存储在文档目录中的视频文件生成缩略图。首先，我只收集

mp4

格式的视频文件：

 override func viewWillAppear(_ animated: Bool) {

        let VIDEO = [collect(files: "mp4"),
                     collect(files: "MP4")]
        videoArray = Array(VIDEO.joined())

    }


 func collect(files:String) -> [String] {

        var fileExtentions = [String]()

        let documentsUrl =  FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

        let fileManager = FileManager.default
        let keys = [URLResourceKey.isDirectoryKey, URLResourceKey.localizedNameKey]
        let options: FileManager.DirectoryEnumerationOptions = [.skipsPackageDescendants, .skipsSubdirectoryDescendants, .skipsHiddenFiles]

        let enumerator = fileManager.enumerator(
            at: documentsUrl,
            includingPropertiesForKeys: keys,
            options: options,
            errorHandler: {(url, error) -> Bool in
                return true
        })


        if enumerator != nil {
            while let file = enumerator!.nextObject() {
                let path = URL(fileURLWithPath: (file as! URL).absoluteString, relativeTo: documentsUrl).path
                if path.hasSuffix(files){
                    fileExtentions.append(path)
                }
            }
        }


        return fileExtentions
    }

然后按如下方式填充tableview的数据：

 func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! VideoCell

        let files = videoArray[indexPath.row]
        let fileURL = URL(fileURLWithPath: files)

        //Vido Title
        cell.videoTitle.text = fileURL.lastPathComponent.removingPercentEncoding!


        cell.thumbnail.image = getThumbnailFrom(path:fileURL)

        return cell
    }

  func getThumbnailFrom(path: URL) -> UIImage? {

        do {

            let asset = AVURLAsset(url: path , options: nil)
            let imgGenerator = AVAssetImageGenerator(asset: asset)
            imgGenerator.appliesPreferredTrackTransform = true
            let cgImage = try imgGenerator.copyCGImage(at: CMTimeMake(0, 5), actualTime: nil)
            let thumbnail = UIImage(cgImage: cgImage)

            return thumbnail

        } catch let error {

            print("*** Error generating thumbnail: \(error.localizedDescription)")
            return nil

        }

    }

我正在从以下视频生成缩略图：

 func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! VideoCell

        let files = videoArray[indexPath.row]
        let fileURL = URL(fileURLWithPath: files)

        //Vido Title
        cell.videoTitle.text = fileURL.lastPathComponent.removingPercentEncoding!


        cell.thumbnail.image = getThumbnailFrom(path:fileURL)

        return cell
    }

  func getThumbnailFrom(path: URL) -> UIImage? {

        do {

            let asset = AVURLAsset(url: path , options: nil)
            let imgGenerator = AVAssetImageGenerator(asset: asset)
            imgGenerator.appliesPreferredTrackTransform = true
            let cgImage = try imgGenerator.copyCGImage(at: CMTimeMake(0, 5), actualTime: nil)
            let thumbnail = UIImage(cgImage: cgImage)

            return thumbnail

        } catch let error {

            print("*** Error generating thumbnail: \(error.localizedDescription)")
            return nil

        }

    }

但最后，当运行应用程序时，编译器给了我以下错误：

***生成缩略图时出错：在此服务器上找不到请求的URL

---

@Lover在我这边测试了getThumbnailFrom（）函数。它在我这边工作得很好。您可能需要检查路径url是否正确。否则，您拥有的视频文件集可能会出现问题

下面是我测试的代码

func getThumbnailFrom() -> UIImage? {

    do {
        let path = Bundle.main.path(forResource: "Video_05", ofType:"mp4")!
        let asset = AVURLAsset(url: URL.init(fileURLWithPath: path) , options: nil)
        let imgGenerator = AVAssetImageGenerator(asset: asset)
        imgGenerator.appliesPreferredTrackTransform = true
        let cgImage = try imgGenerator.copyCGImage(at: CMTimeMake(0, 5), actualTime: nil)
        let thumbnail = UIImage(cgImage: cgImage)

        return thumbnail

    } catch let error {

        print("*** Error generating thumbnail: \(error.localizedDescription)")
        return nil

    }

}

---

最后，通过找到正确的

URL

，解决问题：

let documentsURL = NSURL(fileURLWithPath: NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first!,isDirectory: true ) 

let urlToMyPath = documentsURL.appendingPathComponent(fileURL.lastPathComponent.removingPercentEncoding!)!

---

你的url路径是什么？你能把它粘贴到这里吗？下面是我在模拟器中检查的url。"file:///Users/shreekara/Library/Developer/CoreSimulator/Devices/7E7EF505-E943-40FB-97EB-08EF91B0F7C4/data/Containers/Bundle/Application/589A03B8-A487-4986-888B-69ABE26CF5AE/TextDisplay.app/Video_05.mp4“您使用

Bundle.main.pathFor…

检查了此项？我需要它作为文档目录。”