小编Muh*_*han的帖子

我的下面的代码与swift 4工作得很好但升级到swift 4.2后我收到了这个错误,我浪费了3个小时搜索问题但是失败了.如果有人可以指导我如何解决这个问题.

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

    if postType == 2 {
        let image = info[convertFromUIImagePickerControllerInfoKey(UIImagePickerController.InfoKey)] as! UIImage
        mediaType.image = image
    } else {
        videoURL = info[convertFromUIImagePickerControllerInfoKey(UIImagePickerController.InfoKey.mediaURL)] as? URL
        do {
            let asset = AVURLAsset(url: videoURL!, options: nil)
            let imgGenerator = AVAssetImageGenerator(asset: asset)
            imgGenerator.appliesPreferredTrackTransform = true
            let cgImage = try imgGenerator.copyCGImage(at: CMTime.init(value: 0, timescale: 1), actualTime: nil)
            let thumbnail = UIImage(cgImage: cgImage)
            self.mediaType.image = thumbnail
        } catch {
            print("*** Error generating thumbnail: \(error)")
        } …