public ActionResult Create(CreateViewModel createViewModel)
        {
            if (!ModelState.IsValid)
            {
                return View(createViewModel);
            }

            var selectedDocumentCategory = DocumentCategoryService.FindById(createViewModel.DropDownList_DocumentCategory_Property.SelectedDocumentCategory);

            var document = new Document()
            {
                Name = createViewModel.Name,
                Description = createViewModel.Description,
                DocumentCategoryId = createViewModel.DropDownList_DocumentCategory_Property.SelectedDocumentCategory != -1 ? (int?)createViewModel.DropDownList_DocumentCategory_Property.SelectedDocumentCategory : null,
                DocumentCategory = selectedDocumentCategory
            };

            foreach (string file in Request.Files)
            {
                if (Request.Files[file].ContentLength <= 0 || Request.Files[file] == null)
                    continue;
                string pathToSave = Server.MapPath("~/Files/Documents");
                string oldFilename = Path.GetFileName(Request.Files[file].FileName);
                string fileExtension = Path.GetExtension(Request.Files[file].FileName);
                string uploadFileName = String.Format(Guid.NewGuid() + fileExtension);
                Request.Files[file].SaveAs(Path.Combine(pathToSave, uploadFileName));
                document.OldFileName = Request.Files[file].FileName;
                document.UploadFileUrl = Path.Combine(pathToSave, uploadFileName);
            }

            DocumentService.CreateDocument(document);
            TempData["DocumentId"] = document.DocumentId;
            TempData["DocumentName"] = document.Name;
            TempData["Message"] = DocumentsMessage.CreateSuccess;
            return RedirectToAction("index", "documents");
        }
        public ActionResult Create()
        {
            var dropdownlist_DocumentCategory_Property = new CreateViewModel.DropDownList_DocumentCategory()
            {
                DocumentCategories = DocumentCategoryService.GetDocumentCategories().ToList()
            };

            var createViewModel = new CreateViewModel()
            {
                DropDownList_DocumentCategory_Property = dropdownlist_DocumentCategory_Property
            };

            return View(createViewModel);
        }