public async Task <IActionResult> Create(PDF_Refference pDF_Refference, [Optional] int id)
        {
            if (ModelState.IsValid)
            {
                string refcover      = "Refferences/" + Guid.NewGuid().ToString() + pDF_Refference.Image.FileName;
                string serverFolder1 = Path.Combine(_webHostEnvironment.WebRootPath, refcover);
                await pDF_Refference.Image.CopyToAsync(new FileStream(serverFolder1, FileMode.Create));


                PDF_Refference pdfdoc = new PDF_Refference
                {
                    Doc_id         = pDF_Refference.Doc_id,
                    Description    = pDF_Refference.Description,
                    Refference_url = refcover,
                    Date_modified  = DateTime.Now.ToString()
                };
                _context.Add(pdfdoc);
                await _context.SaveChangesAsync();

                ViewBag.status      = "Refference has been uploaded successfully!";
                ViewBag.imageURL    = "/" + refcover;
                ViewBag.Description = pDF_Refference.Description;
            }

            var posts = _context.Pdf_refference.Where(w => w.Doc_id.ToString() == HttpContext.Session.GetString("docid")).ToList();

            ViewBag.relatedPost = posts;
            return(View());
        }
        public async Task <IActionResult> Edit(int id, [Bind("ID,Doc_id,Refference_url,Date_modified")] PDF_Refference pDF_Refference)
        {
            if (id != pDF_Refference.ID)
            {
                return(NotFound());
            }

            if (ModelState.IsValid)
            {
                try
                {
                    _context.Update(pDF_Refference);
                    await _context.SaveChangesAsync();
                }
                catch (DbUpdateConcurrencyException)
                {
                    if (!PDF_RefferenceExists(pDF_Refference.ID))
                    {
                        return(NotFound());
                    }
                    else
                    {
                        throw;
                    }
                }
                return(RedirectToAction(nameof(Index)));
            }
            return(View(pDF_Refference));
        }