public ActionResult AddFile2Expo(int expoId)
        {
            var exposFilesViewModel = new ExposFilesViewModel
            {
                Title          = "Создание новой выставки",
                AddButtonTitle = "Создать",
                RedirectUrl    = Url.Action("DetailsOfExpo", "Expos", new { _idExpo = expoId }),
            };


            return(View(exposFilesViewModel));
        }
        public async Task <ActionResult> addFile(ExposFilesViewModel exposFilesViewModel)
        {
            if (!ModelState.IsValid)
            {
                return(View(exposFilesViewModel));
            }
            var expoFile = new ExpoFilesFromJson.ExpoFiles()
            {
                expoId = exposFilesViewModel.expoId
            };
            FileRepository fileRepository = new FileRepository();

            byte[] bytes;
            if (exposFilesViewModel.file != null)
            {
                using (Stream inputStream = exposFilesViewModel.file.InputStream)
                {
                    MemoryStream memoryStream = inputStream as MemoryStream;
                    if (memoryStream == null)
                    {
                        memoryStream = new MemoryStream();
                        inputStream.CopyTo(memoryStream);
                    }
                    bytes = memoryStream.ToArray();
                }

                String            fileBase64 = Convert.ToBase64String(bytes);
                FileFromJson.File file       = new FileFromJson.File()
                {
                    authorId = Convert.ToInt16(Session["UserId"]),
                    content  = fileBase64,
                    filename = exposFilesViewModel.file.FileName,
                    fileType = "file",
                    dateTime = DateTimeOffset.Now
                };
                file = await fileRepository.AddFileFromJsonAsync(file);

                expoFile.fileId = file.fileId;
            }
            await expoFilesService.AddExpoFilesFromJsonAsync(expoFile, "expoFile");

            return(RedirectToLocal(exposFilesViewModel.RedirectUrl));
        }