传递到 ViewDataDictionary 的模型项是模型类型，但需要 ViewModels

Question

为了一项作业，我已经为这个错误苦苦挣扎了几天，但我无法修复它，我已经将它展示给另一个人，我们对可能是什么问题感到困惑？ “InvalidOperationException：传入 ViewDataDictionary 的模型项的类型为 'FYP_RSVP_MGMT.Models.GuestList'，但此 ViewDataDictionary 实例需要类型为 'FYP_RSVP_MGMT.ViewModels.GuestListViewModel' 的模型项。”

访客列表控制器:

public class GuestListController : Controller
{
    public IActionResult Index()
    {
        GuestListViewModel guest = new GuestListViewModel();

        return View("Index", guest);
    }

    public IActionResult CreateUpdate(GuestListViewModel guest)
    {
        if(ModelState.IsValid)
        {
            using (var db = DbHelpers.GetConnection()) {

                if(guest.EditableGuest.GuestID == null)
                {
                    /* Count the existing IDs and adds the next ID */
                    guest.EditableGuest.GuestID = guest.Guests.Count;

                    db.Insert<GuestList>(guest.EditableGuest);
                }

                /* If the guest already exists, we are updating the details*/
                else
                {
                    GuestList dbItem = db.Get<GuestList>(guest.EditableGuest.GuestID);

                    TryUpdateModelAsync<GuestList>(dbItem, "EditableGuest");

                    db.Update<GuestList>(dbItem);
                }
            }

            return RedirectToAction("ViewGuestList");
        }

        else
        {
            return View("Index", new GuestList());
        }
       
    }

GuestListViewModel

public class GuestListViewModel
{
    public GuestListViewModel()
    {
        using (var db = DbHelpers.GetConnection())
        {
            this.EditableGuest = new GuestList();

            this.Guests = db.Query<GuestList>("Select * From GuestList").ToList();
        }
    }

    public List <GuestList> Guests { get; set; }

    /* Holds any instance of an object that is being added/edited/deleted etc */
    public GuestList EditableGuest { get; set; }


}

客人名单模型

 public class GuestList
{
    public int? GuestID { get; set; }

    [Required]
    public string GuestName { get; set; }

    [Required]
    public string GuestType { get; set; }

    [Required]
    public string ContactDetails { get; set; }

    public bool PlusOne { get; set; }

    public string PlusOneName { get; set; }

    [Required]
    public string Response { get; set; }
}

Index.cshtml - 表单显示位置

@model FYP_RSVP_MGMT.ViewModels.GuestListViewModel

@{
ViewData["Title"] = "Guest RSVP";
 }

    @using (var form = Html.BeginForm("CreateUpdate", "GuestList", FormMethod.Post))
    {
<div class="container" id="GuestRSVP">

    <br/>
    <br/>
    <br/>

    <h3> Welcome to [Bride] and [Groom]s Wedding</h3>
    <h4>[Church Location]</h4>
    <h4>[Wedding Date and Time]</h4>

    <div class="container"  id="RSVPTable" style="align-content:center">

        <table>

            

            <tr>
                <td>Guest Name: </td>
                <td>@Html.TextBoxFor(m => m.EditableGuest.GuestName)</td>
                <td>@Html.HiddenFor(m => m.EditableGuest.GuestID)</td>
            </tr>

            <tr>
                <td>Guest Type: </td>
                <td>@Html.DropDownListFor(m => m.EditableGuest.GuestType, new List<SelectListItem> { new SelectListItem { Value = "Guest", Text = "Guest" }, new SelectListItem { Value = "Wedding Party", Text = "Wedding Party" } })</td>
            </tr>

            <tr>
                <td>Contact Details: </td>
                <td>@Html.TextBoxFor(m => m.EditableGuest.ContactDetails)</td>
            </tr>

            <tr>
                <td>Plus One: </td>
                <td>@Html.CheckBoxFor(m => m.EditableGuest.PlusOne)</td>
            </tr>

            <tr>
                <td>Plus One Name: </td>
                <td>@Html.TextBoxFor(m => m.EditableGuest.PlusOneName)</td>
            </tr>

            <tr>
                <td>RSVP Response:</td>
                <td>@Html.DropDownListFor(m => m.EditableGuest.Response, new List<SelectListItem> { new SelectListItem { Value = "Accept with Pleasure", Text = "Accept with Pleasure" }, new SelectListItem { Value = "Decline with Regret", Text = "Decline with Regret" } })</td>
            </tr>


            <tr>
                <td><button class="btnSubmitRSVP" type="submit"> @(Model.EditableGuest.GuestID > 0? "Update": "Add") </button></td>
                <td></td>
            </tr>

        </table>


    </div>


</div>

}

我们无法弄清楚为什么传递的是模型而不是视图模型？我的代码没有引用模型？任何帮助将不胜感激！

Answer 1

我会说它来自这里：

尽管您承诺会在页面顶部发送 GuestListViewModel，但您还是在 else 中发送了 GuestList：

传递到 ViewDataDictionary 的模型项是模型类型，但需要 ViewModels

The model item passed into the ViewDataDictionary is of type Models but needs ViewModels

c#

model-view-controller

asp.net-mvc