c# - Linq GroupBy 匿名类型错误 MVC4

Question

我有下面的代码，它使用组来选择不同的值。智能和代码中断显示查询按预期工作。

public ActionResult _PortfoliosbyCountry()
    {
        var portfolios = db.Portfolios;
        var query = (from t in portfolios
                     group t by new { t.UserId, t.CountryId,t.PortfolioTypeId }
                         into grp
                         select new 
                         {
                             grp.Key.CountryId,
                             grp.Key.PortfolioTypeId,
                             grp.Key.UserId  
                         }).ToList();


        return PartialView(query);
    }

模型

namespace RefST.Models
{
public class Portfolio
{
    [Key]
    public int PId { get; set; }
    [Required]
    public string Title { get; set; }
    [ScaffoldColumn(false)]
    public DateTime DatePosted { get; set; }
    [ScaffoldColumn(false)]
    public DateTime LastEdited { get; set; }
    [AllowHtml][Required]
    public string Body { get; set; }
    public int UserId {get; set; }     
    public int CountryId { get; set; }
    public int PortfolioTypeId { get; set; }
    public virtual Country Country { get; set; }
    public virtual PortfolioType PortfolioType { get; set; }
}
}

问题是 razor view 给出了以下错误 传入字典的模型项的类型为:'System.Collections.Generic.List 1[<>f__AnonymousType19 3[System.Int32,System.Int32,System.Int32]]'，但此字典需要类型为'System.Collections.Generic.IEnumerable`1[RefST.Models.Portfolio]'的模型项。

@model IEnumerable<RefST.Models.Portfolio>

<p>
   @Html.ActionLink("Create New", "Create")
</p>

<table>
 <tr>

    <th>
        @Html.DisplayNameFor(model => model.UserId)
    </th>

    <th>
        @Html.DisplayNameFor(model => model.CountryId)
    </th>


    <th>
        @Html.DisplayNameFor(model => model.PortfolioTypeId)
    </th>

    <th></th>
 </tr>

 @foreach (var b in Model) {
  <tr>
    <td>
        @Html.DisplayFor(modelItem => b.UserId)
    </td>
    <td>
        @Html.DisplayFor(modelItem => b.CountryId)
    </td>
    <td>
        @Html.DisplayFor(modelItem => b.PortfolioTypeId)
    </td>
  </tr>
 }
 </table>

如果有人能指出正确的方向，我将不胜感激

Answer 1

我认为在这一行中你可以这样做:

select new PortFolio
                     {
                        countryId= grp.Key.CountryId,
                        PortfolioTypeId= grp.Key.PortfolioTypeId,
                        UserId= grp.Key.UserId,
                        //Add others members with default value
                        Titel=string.Empty;
                        ....  
                     }).ToList();

所以你确定你发送了一个IEnumerable<Portfolio>作为 Model