public async Task <ActionResult> Checkout()
{
var list2 = JsonConvert.DeserializeObject <List <CartModel> >(TempData["cart"] as string);
//var list2 = ViewData["cart"] as List<CartModel>;
var model = new InvoiceModel();
var userId = User.FindFirstValue(ClaimTypes.NameIdentifier);
var user = await _userManager.FindByIdAsync(userId);
TempData["user"] = JsonConvert.SerializeObject(user);
return(View(model.GenerateInvoice(user, list2)));
}