Linq Query of ViewModel not DomainModel

Question

当浏览Google查找使用MVC Curlad设置的示例时，我总是发现详细信息页面被遗漏了，因为很重要，特别是如果您想使用视图模型。

我遇到的问题是，Visual Studio 中的典型 MVC 应用程序设置将使用 CRUD，但所有视图页面都将使用域模型而不是视图模型。

所以我想从两个基于整数的模型中提取数据，如果它是一个模型：

        public ActionResult Details(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
            Asset Assets = db.Assets.Find(id);
            if (id == null)
            {
                return HttpNotFound();
            }
            return View();
        }

但是我怎么拉两套呢？这是我对视图模型的 linq 查询：

var ASSPATVM = (from s in db.Assets
                        join cp in db.PATs on s.AssetID equals cp.AssetID into AP
                        from subpat in AP.DefaultIfEmpty()

                        select new ASSPATVM
                        {
                            AssetID = s.AssetID,
                            ProductName = s.ProductName,
                            ModelName = s.ModelName,
                            SupplierName = s.SupplierName,
                            ManufacturerName = s.ManufacturerName,
                            SerialNo = s.SerialNo,
                            PurchaseDate = s.PurchaseDate,
                            PoNo = s.PoNo,
                            Costing = s.Costing,
                            TeamName = s.TeamName,
                            StaffName = s.StaffName,
                            InspectionDocumnets = subpat.InspectionDocumnets ?? String.Empty,
                            InspectionOutcomeResult = subpat.InspectionOutcomeResult
                        });

编辑

所以我试过：

 public ActionResult Details(int? AssetID)
        {
            var ASSPATINCVM = (from s in db.Assets
                                  join cp in db.PATs on s.AssetID equals cp.AssetID into AP
                                  from subASSPAT in AP.DefaultIfEmpty()
                                        join ci in db.INSs on s.AssetID equals ci.AssetID into AI
                                        from subASSINC in AI.DefaultIfEmpty()

                                        select new ASSPATINCVM()
                                  {
                                      AssetID = s.AssetID,
                                      ProductName = s.ProductName,
                                      ModelName = s.ModelName,
                                      SupplierName = s.SupplierName,
                                      ManufacturerName = s.ManufacturerName,
                                      SerialNo = s.SerialNo,
                                      PurchaseDate = s.PurchaseDate,
                                      PoNo = s.PoNo,
                                      Costing = s.Costing,
                                      TeamName = s.TeamName,
                                      StaffName = s.StaffName,
                                      WarrantyEndDate = subASSPAT.WarrantyEndDate,
                                      InspectionDate = subASSPAT.InspectionDate,
                                      InspectionOutcomeResult = subASSPAT.InspectionOutcomeResult,
                                      InspectionDocumnets = subASSPAT.InspectionDocumnets ?? String.Empty,
                                      InspectionDueDate = subASSPAT.InspectionDueDate
                                        });
            return View(ASSPATINCVM);
        }

我收到错误：

The model item passed into the dictionary is of type 'System.Data.Entity.Infrastructure.DbQuery`1[Assets.Areas.CCS.Models.ASSPATINCVM]', but this dictionary requires a model item of type 'Assets.Areas.CCS.Models.ASSPATINCVM'.

所以后来我尝试列出((

InspectionDate = subASSPAT.InspectionDate,
                                      InspectionOutcomeResult = subASSPAT.InspectionOutcomeResult,
                                      InspectionDocumnets = subASSPAT.InspectionDocumnets ?? String.Empty,
                                      InspectionDueDate = subASSPAT.InspectionDueDate
                                        }).List();
@model List<Assets.Areas.CCS.Models.ASSPATINCVM>

但现在的抱怨是

List<ASSPATINCVM>' does not contain a definition for 'ModelName'

更新

视图模型：

using Assets.Models;
using System;
using System.ComponentModel.DataAnnotations;
namespace Assets.Areas.CCS.Models
{
    public class ASSPATINCVM
    {

        public int AssetID { get; set; }
        public string SerialNo { get; set; }
        public string PoNo { get; set; }
        public float? Costing { get; set; }
        public string InspectionDocumnets { get; set; }
        public Product ProductName { get; set; }
        public InspectionOutcome InspectionOutcomeResult { get; set; }
        public Model ModelName { get; set; }
        public BudgetCode Code { get; set; }
        public AssetType AssetTypeName { get; set; }
        public Manufacturer ManufacturerName { get; set; }
        public Staff StaffName { get; set; }
        public Team TeamName { get; set; }
        public Supplier SupplierName { get; set; }
        [DataType(DataType.Date)]
        [DisplayFormat(DataFormatString = "{0:dd/MM/yy}", ApplyFormatInEditMode = true)]
        public DateTime? PurchaseDate { get; set; }
        public DateTime? WarrantyEndDate { get; set; }
        public DateTime? InspectionDate { get; set; }
        public DateTime? InspectionDueDate { get; internal set; }
    }
}

详细信息页面的一部分：

@model Assets.Areas.CCS.Models.ASSPATINCVM
@{
    ViewBag.Title = "Details";
}
<h2>Details</h2>
<div>
    <h4>ClinicalAsset</h4>
    <hr />
    <dl class="dl-horizontal">
        <dt>
            @Html.DisplayNameFor(model => model.ModelName)
        </dt>
        <dd>
            @Html.DisplayFor(model => model.ModelName)
        </dd>
        <dt>
            @Html.DisplayNameFor(model => model.AssetTypeName)
        </dt>
        <dd>

Answer 1

您的控制器操作返回一个IEnumerable<ASSPATINCVM>但您的视图需要 ClinicalASSPATINCVM 的单个实例，请参阅视图中的以下行：

@model Assets.Areas.Clinical.Models.ClinicalASSPATINCVM

您应该能够将视图更新为模型类的相应IEnumerable类型ASSPATINCVM，然后循环访问列表，如下所示：

@model IEnumerable<Assets.Areas.CCS.Models.ASSPATINCVM>
@{
    ViewBag.Title = "Details";
}
<h2>Details</h2>
<div>
    <h4>ClinicalAsset</h4>
    <hr />
    <dl class="dl-horizontal">
    @foreach(var m in Model)
    {
        <dt>
            @Html.DisplayNameFor(model => model[0].ModelName)
        </dt>
        <dd>
            @m.ModelName
        </dd>
    }
    </dl>
</div>

编辑：

根据注释，您需要更新查询以返回 ASSPATINCVM 的单个实例，您可以通过以下方式执行此操作：

    public ActionResult Details(int? AssetID)
    {
        var ASSPATINCVM = (from s in db.Assets
                              join cp in db.PATs on s.AssetID equals cp.AssetID into AP
                              from subASSPAT in AP.DefaultIfEmpty()
                                    join ci in db.INSs on s.AssetID equals ci.AssetID into AI
                                    from subASSINC in AI.DefaultIfEmpty()

                                    select new ASSPATINCVM()
                              {
                                  AssetID = s.AssetID,
                                  ProductName = s.ProductName,
                                  ModelName = s.ModelName,
                                  SupplierName = s.SupplierName,
                                  ManufacturerName = s.ManufacturerName,
                                  SerialNo = s.SerialNo,
                                  PurchaseDate = s.PurchaseDate,
                                  PoNo = s.PoNo,
                                  Costing = s.Costing,
                                  TeamName = s.TeamName,
                                  StaffName = s.StaffName,
                                  WarrantyEndDate = subASSPAT.WarrantyEndDate,
                                  InspectionDate = subASSPAT.InspectionDate,
                                  InspectionOutcomeResult = subASSPAT.InspectionOutcomeResult,
                                  InspectionDocumnets = subASSPAT.InspectionDocumnets ?? String.Empty,
                                  InspectionDueDate = subASSPAT.InspectionDueDate
                                    }).FirstOrDefault();
        return View(ASSPATINCVM);
    }

Answer 2

基于 jcruz 的答案：

我还需要在 id 和 AssetID 之间添加一个链接：

var ASSPATINCVM = (from s in db.Assets
                                       join cp in db.PATs on s.AssetID equals cp.AssetID into AP
                                       from subASSPAT in AP.DefaultIfEmpty()
                                       join ci in db.INSs on s.AssetID equals ci.AssetID into AI
                                       from subASSINC in AI.DefaultIfEmpty()

                                       select new ASSPATINCVM
                                       {
                                           AssetID = s.AssetID,
                                           AssetTypeName = s.AssetTypeName,
                                           ProductName = s.ProductName,
                                           ModelName = s.ModelName,
                                           SupplierName = s.SupplierName,
                                           ManufacturerName = s.ManufacturerName,
                                           SerialNo = s.SerialNo,
                                           PurchaseDate = s.PurchaseDate,
                                           PoNo = s.PoNo,
                                           Costing = s.Costing,
                                           TeamName = s.TeamName,
                                           StaffName = s.StaffName,
                                           WarrantyEndDate = subASSPAT.WarrantyEndDate,
                                           InspectionDate = subASSPAT.InspectionDate,
                                           InspectionOutcomeResult = subASSPAT.InspectionOutcomeResult,
                                           InspectionDocumnets = subASSPAT.InspectionDocumnets ?? String.Empty,
                                           InspectionDueDate = subASSPAT.InspectionDueDate
                                       }).FirstOrDefault(x => x.AssetID == id);