public ActionResult Create(Categories category)
 {
     if (category != null && ModelState.IsValid)
     {
         this._categoryService.Create(category);
         return RedirectToAction("index");
     }
     else
     {
         return View(category);
     }
 }
 public ActionResult Edit(Categories category)
 {
     if (category != null && ModelState.IsValid)
     {
         this.categoryRepository.Update(category);
         return View(category);
     }
     else
     {
         return RedirectToAction("index");
     }
 }
        public IResult Update(Categories instance)
        {
            if (instance == null)
            {
                throw new ArgumentNullException();
            }

            IResult result = new Result(false);
            try
            {
                this._repository.Update(instance);
                result.Success = true;
            }
            catch (Exception ex)
            {
                result.Exception = ex;
            }
            return result;
        }