来自 UiImagepicker 视频的缩略图

Thumbnail from UiImagepicker video

我使用 UIImagePickerController 从相册中挑选了一个视频,并尝试使用以下函数从中生成缩略图:

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

        do {

            let asset = AVURLAsset.init(url: path)
            print(asset.url)
            let imgGenerator = AVAssetImageGenerator(asset: asset)
            imgGenerator.appliesPreferredTrackTransform = true
            let cgImage = try imgGenerator.copyCGImage(at: CMTimeMake(0, 1), actualTime: nil)
            let thumbnail = UIImage(cgImage: cgImage)

            return thumbnail

        } catch let error {

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

        }

    }

但是我在日志上看到了 *** Error generating thumbnail: Cannot Open

[discovery] errors encountered while discovering extensions: Error Domain=PlugInKit Code=13 "query cancelled" UserInfo={NSLocalizedDescription=query cancelled}

知道为什么吗?它是 iOS 11 台设备中的错误,知道如何解决此问题并生成缩略图吗?

谢谢!

好的,这是关于请求权限,我已经在我的应用程序开始时请求了。还是要再问一遍,不知道为什么,总之有效

PHPhotoLibrary.requestAuthorization({ (status: PHAuthorizationStatus) -> Void in
            ()

            if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.authorized {
                print("creating 2")
                if let thumbnailImage = self.getThumbnailFrom(path: self.facebookVideoURL){
                    self.thumbnailImageForVideo.image = thumbnailImage
                }
            }

        })