public ActionResult Edit(int id)
        {
            var item = _appservice.GetItem(id);
            if (item == null)
            {
                return ItemNotFound("DataItem with id {0} does not exists!", id);
            }

            DataItemViewModel model = new DataItemViewModel();
            model.Item = item;
            return View(model);
        }
        public ActionResult Edit(int id, DataItemViewModel model)
        {
            if (ModelState.IsValid)
            {
                var item = _appservice.GetItem(id);
                if (item == null)
                {
                    return ItemNotFound("DataItem with id {0} does not exists!", id);
                }

                _appservice.UpdateItem(model.Item);

                return RedirectToAction("Index");
            }

            return View(model);
        }
 public ActionResult Index()
 {
     DataItemViewModel model = new DataItemViewModel();
     model.Data = _appservice.GetDataItems();
     return View(model);
 }