public ActionResult Create(int id)
 {
     ViewBag.viewID = id;
     Category category = new Category();
     category.parentID = id;
     category.sortNum = db.Category.Where(x => x.parentID == id).Count() + 1;
     return View(category);
 }
        public ActionResult Create(Category category)
        {
            if (ModelState.IsValid)
            {
                db.Category.Add(category);
                db.SaveChanges();
                return RedirectToAction("CategorySpryList", new { id = category.parentID });
            }

            return View(category);
        }