Question

我在将变量从控制器传递到视图时遇到问题。我创建了一个动作结果，允许用户在餐馆菜单中添加膳食。我需要html操作链接中的menuID才能访问菜单详细信息页面。但是当我运行页面时ViewData["MenuID"]返回为null，即使menuID在控制器操作结果中有值。还有另一种方法可以将数据从控制器发送到视图吗？

创建操作结果

[HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create(MealviewModel model, int? menuID)
        {
            if (menuID == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            else
            {
                ViewData["MenuID"] = menuID;
                if (ModelState.IsValid)
                {
                    var manager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));
                    var currentUser = manager.FindById(User.Identity.GetUserId());


                    var currentrestaurant = (from r in db.Restaurants
                                             where r.UserID == currentUser.Id
                                             select r).First<Restaurant>().id;

                    var currentmenu = (from m in db.Menus
                                       where m.Restaurantid == currentrestaurant
                                       select m).First<Menu>().Id;
                    var meal = new Meal() { Name = model.Name, Description = model.Description, Price = model.Price, MenuID = menuID, Catergory = model.Catergory };

                    db.Meals.Add(meal);
                    db.SaveChanges();
                    return RedirectToAction("Create", new { MenudID = menuID });

                }
            }
            return View();

        }

创建CSHTML页面

@model BiteWebsite.Models.MealviewModel
@using BiteWebsite.Models;

@{
    ViewBag.Title = "Add Items to Your Menu";
}

<h2>Add Items to Your Menu</h2>

@using (Html.BeginForm())
{

    var ID = ViewData["MenuID"];
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <hr />
        @Html.ValidationSummary(true)
        <div class="form-group">
            @Html.LabelFor(model => model.Catergory, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownList("Catergory", new SelectList(new[] {"Chef Specials","Deserts","Drinks","Main Courses","Sides",
                                                                "Starters" ,"Salads"}))
            </div>
        </div>
        <div class="form-group">
            @Html.LabelFor(model => model.Name, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Name)
                @Html.ValidationMessageFor(model => model.Name)
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Description, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Description, new { @cols = "80", @rows = "4" })
                @Html.ValidationMessageFor(model => model.Description)
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Price, new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Price)
                @Html.ValidationMessageFor(model => model.Price)
            </div>
        </div>

        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Add Item" class="btn btn-default" />
                <div class="btn btn-default">
                    @Html.ActionLink("View Menu", "Menu", "Details", new { Id = ID })
                </div>
            </div>

        </div>
    </div>
}

Answer 1

因为您正在返回重定向操作。你应该使用tempdata或session变量来保存menuid中的值，并且当它是重定向行为时应保存该值。

Answer 2

当您进行重定向时，您将丢失ViewData的内容。虽然保留了TempData，但如果可以重定向，则可以使用它。我不了解ViewBag，所以你可以测试一下。

Answer 3

您已经在视图模型中传递其他值，为什么不在该视图模型中创建一个新属性并将其传递给视图？

从控制器传递数据以查看ASP.NET

3 个答案: