如何使用avplayer从documentdirectory播放视频文件

我正在ios中创建视频播放器应用程序，如果我将mp4文件存储在bundle资源中，或者如果我流式处理url，它可以正常工作，但是如果我将文件存储在document目录中，并且我正在尝试使用avplayer，如果我对document目录中的脱机文件进行不同的处理，它就不会播放。
代码：

let fileManager = FileManager()
        let destinationURLForFile = URL(fileURLWithPath: documentDirectoryPath.appendingFormat("/myvideo.mp4"))
   self.playVideo(filePath: destinationURLForFile.path)


   func playVideo(filePath:String)
    {
        var playerItem = AVPlayerItem.init(url:URL.init(string: filePath)!)

        var player = AVPlayer(playerItem: playerItem)
        var playerLayer = AVPlayerLayer(player: player)
        playerLayer.frame = self.view.frame
        self.view.layer.addSublayer(playerLayer)
        player.play()

    }

最佳答案：

SWIFT 3/4 100%
录像机打开摄像机

@IBAction func RecordAction(_ sender: Any) {

        if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.camera){
            print("CameraAvailable")
            let imagePicker = UIImagePickerController()
            imagePicker.delegate = self
            imagePicker.sourceType = .camera
            imagePicker.mediaTypes = [kUTTypeMovie as String]
            imagePicker.allowsEditing = false
            imagePicker.showsCameraControls = true

            self.present(imagePicker,animated: true, completion: nil)
        }

        else{
            print("CameraNotAvailable")
        }
    }

保存到文档目录

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        // recover video URL
        let url = info[UIImagePickerControllerMediaURL] as? URL
        // check if video is compatible with album
        let compatible: Bool = UIVideoAtPathIsCompatibleWithSavedPhotosAlbum((url?.path)!)
        // save
        if compatible {
            UISaveVideoAtPathToSavedPhotosAlbum((url?.path)!, self, nil, nil)
            print("saved!!!! \(String(describing: url?.path))")

        }
        videopath = url //save url to send next function play video
        dismiss(animated: true, completion: nil)
    }
//   error
    func video(_ videoPath: String, didFinishSavingWithError error: Error?, contextInfo: UnsafeMutableRawPointer) {
    }

从文档目录播放视频

 @IBAction func playvideo(_ sender: Any)
    {
        let player = AVPlayer(url: videopath!)  // video path coming from above function

        let playerViewController = AVPlayerViewController()
        playerViewController.player = player
        self.present(playerViewController, animated: true) {
            playerViewController.player!.play()
        }
}