如何使用DistinctBy并选择在asp.net中显示哪一行

Question

我为每个NumDemande提供了几个id_demande。 我想显示我的demandes distinctBY NumDemande，但我不想选择与该NumDemande关联的第一个id_demande，我想选择包含要显示的id_Etat最大值的id_demande。

我的控制器

 public ActionResult ListeDemande()
    {
        traçabilitérepository=new TraçabilitéDemandeRepository(db);
        var listdemandes = (from d in db.Demande_Gabarit
                            join t in db.Traçabilité_Demande_Gabarit
                                on d.id_demande equals t.iddemande into ThisList
                            from t in ThisList.DefaultIfEmpty()

                            select new
                            {
                                NumDemande = d.NumDemande,
                                Emetteur = d.Emetteur,
                                Date = d.Date,
                                Ligne = d.Ligne.designation,
                                Etat = t.Etat_Demande_Gabarit.EtatDemande

                            }).ToList().Select(x => new DemandeViewModel()
                            {
                                NumDemande = x.NumDemande,
                                Emetteur = x.Emetteur,
                                Date = x.Date,
                                designation = x.Ligne,
                                EtatDemande = x.Etat
                            });


        return View(listdemandes);
    }

我的观点

@model IEnumerable<ViewModel.DemandeViewModel>

@{
    ViewBag.Title = "TraitementDemande";
}



<div class="col-xs-12">
    <div class="box">
        <h2>Liste des demandes</h2>
        @using (Html.BeginForm("Recherche", "Demandes", FormMethod.Get))
        {
            /*<div class="box-tools">
                <div class="input-group input-group-sm" style="width: 150px;">
                    <input type="text" name="table_search" class="form-control pull-right" placeholder="Search">

                    <div class="input-group-btn">
                        <button type="submit" class="btn btn-default"><i class="fa fa-search"></i></button>
                    </div>
                </div>
            </div>*/

            @Html.TextBox("Search");<input type="submit" value="Search" />
        }

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


        <table class="table table-striped">
            <tr>
                <th>
                    N° Demande
                </th>
                <th>
                    @Html.DisplayNameFor(model => model.Emetteur)
                </th>
                <th>
                    @Html.DisplayNameFor(model => model.Date)
                </th>

                <th>
                    Ligne
                </th>
                <th>
                    Etat
                </th>
                <th></th>
            </tr>

            @foreach (var item in Model)
            {
                <tr>

                    <td>
                        @Html.DisplayFor(modelItem => item.NumDemande)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => item.Emetteur)
                    </td>

                    <td>
                        @Html.DisplayFor(modelItem => item.Date)
                    </td>

                    <td>
                        @Html.DisplayFor(modelItem => item.designation)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => item.EtatDemande)
                    </td>
                    <td>

                        @Html.ActionLink("Details", "Details", new { num = item.NumDemande,iddemande=item.id_demande })

                    </td>
                </tr>
            }

        </table>
    </div>
</div>

请帮助，谢谢。