傳遞到字典中的模型項的類型為'System.Collections.Generic.List，但是此字典需要類型為的模型項

Question

我有一個ASP.NET MVC 5應用程序，用戶可以在其中查看項目索引。 我添加了另一個名為“應用程序”的數據庫表，該表將存儲用戶在從索引中申請項目時創建的應用程序對象。 應用程序模型：

public class Application
{
    public int ApplicationId { get; set; }
    public int ProjectId { get; set; }
    public string UserId { get; set; }
    public string CoverLetter { get; set; }

}

其中ProjectId和UserId是外鍵（分別來自dbo.Projects和dbo.AspNetUsers）

現在，對於Projects索引視圖，我已將視圖模型更改為ApplicationTwoViewModel：

 public class ApplicationTwoViewModel
    {
        public IEnumerable<Project> Model1 { get; set; }
        public Application Model2 { get; set; }
    }

Index.cshtml：

@using Leepio.Models
@using Microsoft.AspNet.Identity
@model ApplicationTwoViewModel

@{
    ViewBag.Title = "Index";
}

<h2>Index</h2>

<p>
    @Html.ActionLink("Create New", "Create" ,"Projects")
</p>
<table class="table">
    <tr>
        <th>
            @Html.ActionLink("Title", "Index", "Projects", new {SortOrder = (ViewBag.SortOrder==null?"Asc":(ViewBag.SortOrder=="Asc"?"Desc":"Asc")), SortBy = "Title"})

        </th>
        <th>
            @Html.ActionLink("Application Deadline", "Index", "Projects", new {SortOrder = (ViewBag.SortOrder == null ? "Asc" : (ViewBag.SortOrder == "Asc" ? "Desc" : "Asc")), SortBy = "ApplicationDeadline"}) <br/>
            @Html.ActionLink("Hourly Rate (DKK)", "Index", "Projects", new { SortOrder = (ViewBag.SortOrder == null ? "Asc" : (ViewBag.SortOrder == "Asc" ? "Desc" : "Asc")), SortBy = "HourlyRate" })
        </th>
       <th>
            @Html.ActionLink("Skill requirements", "Index", "Projects", new { SortOrder = (ViewBag.SortOrder == null ? "Asc" : (ViewBag.SortOrder == "Asc" ? "Desc" : "Asc")), SortBy = "RequiredSkills" })
        </th>


    </tr>

@foreach (var item in Model.Model1) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.Title)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.ApplicationDeadline)<br/>
            @Html.DisplayFor(modelItem => item.HourlyRate)
        </td>
       <td>
            @Html.DisplayFor(modelItem => item.RequiredSkills)
        </td>


        <td>

            @if(item.UserId == User.Identity.GetUserId()) 

            {
                @Html.ActionLink("Edit", "Edit", "Projects", new {id = item.ProjectId})

                @Html.ActionLink("Delete", "Delete", "Projects", new {id = item.ProjectId}) 
            }

            @Html.ActionLink("Details", "Details", "Projects", new {id = item.ProjectId}) |
            @Html.ActionLink("Apply", "Index", "Applications", new { id = item.ProjectId }) |
        </td>
    </tr>
}

</table>
@{
    double TotalPage = @ViewBag.TotalPages;
}

<ul class="pagination">
    @for (int i = 1; i <= TotalPage; i++)
    {

        if (i == ViewBag.Page)
        {
            <li class="active"> @Html.ActionLink(i.ToString() + " ", "Index", "Projects", new { SortOrder = (ViewBag.SortOrder == null ? "Asc" : ViewBag.SortOrder), SortBy = (ViewBag.SortBy == null ? "Title" : ViewBag.SortBy), Page = i })</li>
        }
        else
        {
            <li>
                @Html.ActionLink(i.ToString() + " ", "Index", "Projects", new { SortOrder = (ViewBag.SortOrder == null ? "Asc" : ViewBag.SortOrder), SortBy = (ViewBag.SortBy == null ? "Title" : ViewBag.SortBy), Page = i })
            </li>
        }

    }
</ul>

當然，我正在使用Model.Model1和Model.Model2。

嘗試打開Projects索引視圖時，我得到以下信息： 傳遞到字典中的模型項的類型為'System.Collections.Generic.List`1 [Leepio.Models.Project]'，但是此字典需要的模型項為鍵入“ Leepio.Models.ApplicationTwoViewModel”。

ProjectsController：

 public ActionResult Index(string SortOrder, string SortBy, string Page)
        {
            ViewBag.SortOrder = SortOrder;
            ViewBag.SortBy = SortBy;
            var projects = db.Projects.ToList();
            var model = new ApplicationTwoViewModel
            {
                Model1 = new List<Project>(projects),
                Model2 = new Application
                {

                    UserId = User.Identity.GetUserId(),
                    ProjectId = 11,
                    CoverLetter = "asdf",
                    ApplicationId = 23,
                }
            };

            //bunch of code I cut out regarding the sorting



        ViewBag.TotalPages =     Math.Ceiling(db.Projects.ToList().Count()/10.0);
        int page = int.Parse(Page == null ? "1" : Page);
        ViewBag.Page = page;
        projects = projects.Skip((page - 1) * 10).Take(10).ToList();
        return View(projects);

    }

我已經嘗試初始化Model2硬編碼，即使我不想這樣。 什么可以解決此錯誤？ 我感覺初始化已關閉，但不確定

Answer 1

您的View希望您接受ApplicationTwoViewModel類的實例，如Index.cshtml View頂部所示：

@model ApplicationTwoViewModel

因此，您只需要創建一個並傳遞它，這應該非常容易，因為您已經在Controller Action中構建了它：

// Pass the model to your View
return View(model);

由於您是在初始化后顯式地對其進行編輯，因此您可能要在return調用之前執行以下操作，並確保對Model中的集合也進行了其他任何操作（即排序和過濾）：

// Perform your paging at the model level
model.Model1 = model.Model1.Skip((page - 1) * 10).Take(10).ToList();
// Now return it
return View(model);