private void View_OnUpdateItem(object sender, IdEventArgs e)
        {
            Category item = this.categoryService.GetById(e.Id);

            if (item == null)
            {
                // The item wasn't found
                this.View.ModelState.AddModelError("", String.Format("Item with id {0} was not found", e.Id));
                return;
            }
            this.View.TryUpdateModel(item);
            if (this.View.ModelState.IsValid)
            {
                this.categoryService.UpdateCategory(item);
            }
        }
 private void View_OnDeleteItem(object sender, IdEventArgs e)
 {
     this.categoryService.DeleteCategory(e.Id);
 }