如何在mvc2中使用TrypUpdateModel更新ViewData

问题描述

|| 我的视图填充了模型属性，并且一些下拉列表经过了硬编码，并通过viewdata传递给视图，问题是Trupdatemodel仅更新模型值，我无法更新viewdata值，以下是更新模型但未更新模型的代码viedata下拉列表： 视图：

<div class=\"editor-field\">
                    <% if (ViewBag.mode != \"edit\")
                       { %>
                    <%: Html.TextBoxFor(model => model.Date)%>
                    <%}else{%>
                        <%: Html.TextBoxFor(model => model.Date,new { @Value = Model.Date.ToShortDateString() })%>
                    <%} %>
                    <%: Html.ValidationMessageFor(model => model.Date) %>
                </div></td></tr><tr><td>Experience level</td><td><div class=\"editor-field\">
                    <%: Html.DropDownListFor(model => model.ExperienceLevelID,(SelectList)ViewData[\"Experience\"],\"--select--\")%>
                    <%: Html.ValidationMessageFor(model => model.ExperienceLevelID) %>
                </div></td></tr>

                 <tr><td>No of Attendees</td><td><div class=\"editor-field\">

              <%-- <%: Html.DropDownList(\"attendees1\",(SelectList)ViewData[\"attendees1\"],\"--select--\")%>--%>
               <% if (ViewBag.mode != \"edit\")
                  { %>

                <%: Html.DropDownList(\"attendees1\",ViewData[\"attendees1\"] as SelectList,\"--select--\")%>
               <%}else{%>
               <%: Html.DropDownList(\"attendees1\")%>
               <%} %>
                &nbsp;&nbsp; <label>£</label>&nbsp;<%: Html.TextBox(\"attendeeCost\",ViewData[\"txtAttendees\"],new { maxlength = \"5\",style = \"width:40px;\" })%> <label>Price/Unit</label>
                </div></td></tr>

                <tr><td>Second Driver</td><td> <div class=\"editor-field\">

                    <label>£</label>&nbsp;<%: Html.TextBoxFor(model => model.SecondDriverPrice,style = \"width:40px;\" })%> <label>Price</label>
                    &nbsp;&nbsp; <%: Html.CheckBoxFor(model => model.SecondDriver) %><label>Free</label>
              </div></td></tr>

                <tr><td>No of Helmets</td><td><div class=\"editor-field\">
               <% if (ViewBag.mode != \"edit\")
                  { %>
               <%: Html.DropDownList(\"helmets\",ViewData[\"size\"] as SelectList,\"--select--\")%>
               <%}else{%>
                <%: Html.DropDownList(\"helmets\",\"--select--\")%>
               <%} %>
                &nbsp;&nbsp; <label>£</label>&nbsp;<%: Html.TextBox(\"unitCosthelmet\",ViewData[\"txtHelmet\"],style = \"width:40px;\" })%> <label>Price/Unit</label>
                </div></td></tr>

控制器：

 [HttpPost]
    public ActionResult Edit(int id,FormCollection collection)
    {


        ViewBag.mode = \"edit\";

        // for dropdown track
        ITrackRepository trackResp = new TrackRepository();
        IQueryable<Object> tracks = trackResp.GetVenuesSelectlist();
        ViewData[\"Venue\"] = new SelectList(tracks,\"VenueID\",\"Name\");

        // for dropdown for event type
        ITrackdayRepository trackdayResp = new TrackdayRepository();
        IQueryable<EventType> eventTypes = trackdayResp.GetAllEventTypes();
        ViewData[\"EventTypes\"] = new SelectList(eventTypes,\"ID\",\"Name\");

        // for dropdown experience
        IExperienceLevelRepository expLevelResp = new ExperienceLevelRepository();
        IQueryable<ExperienceLevel> expLevel = expLevelResp.GetAllExperienceLevels().OrderBy(ExperienceLevel => ExperienceLevel.Name);
        ViewData[\"Experience\"] = new SelectList(expLevel,\"Name\");

        // dropdown for helmets
        IProductRepository helmetResp = new ProductRepository();
        Product productHelmet = helmetResp.GetProd(id);

        var attendeesList = Enumerable.Range(1,80).Select(x => new SelectListItem { Value = x.ToString(),Text = x.ToString() });
        ViewData[\"attendees1\"] = new SelectList(attendeesList.ToList(),\"Value\",\"Text\");


        // dropdown for helmets 
        var helmetsList = Enumerable.Range(1,200).Select(x => new SelectListItem { Value = x.ToString(),Text = x.ToString() });
        ViewData[\"helmets\"] = new SelectList(helmetsList.ToList(),\"Text\");

        //ViewBag.helmet = new SelectList(helmets.ToList(),\"Text\",product.QtyAvailable);

        // dropdown for garages
        var garagesList = Enumerable.Range(1,50).Select(x => new SelectListItem { Value = x.ToString(),Text = x.ToString() });
        ViewData[\"garages\"] = new SelectList(garagesList.ToList(),\"Text\");

        Event trackday = trackdayResp.GetEvent(id);

        TryUpdateModel(trackday,collection);


        if (ModelState.IsValid)
        {
           // product.DateModified = DateTime.Now;
            trackday.DateModified = DateTime.Now;
            TempData[\"msg\"] = trackdayResp.Save().ToString();
            helmetResp.Save();
            return RedirectToAction(\"Index\");
        }
        else
        {
            return View(\"Create\");
        }


    }

    

解决方法

        您需要在模型中为

TryUpdateModel

更新要更新的数据才能更新这些值。如果仅将它们放在ViewData中，则数据将仅传递到视图，并且控制器无法使用

TryUpdateModel

更新这些值。 您需要将ViewData中当前存在的选择列表数据包括到

Event

对象中，或创建一个将包含要更新的值的对象。然后使用

TryUpdateModel

将使用发布的值更新该数据。当您创建此新对象或将其添加到“ 4”时，请在该对象上强烈键入视图，因此您无需在视图中进行ViewData强制转换。