Question

我想使用ViewModel显示相关表格的详细信息视图。

所以我已经创建了详细信息操作方法，但它无法正常工作。

 public ActionResult Details(int id)
    {

        IQueryable<EntryViewModel> query = (from cat in _db.Categories
                 join en in _db.Entries on cat.Id equals en.CategoryId
                 where en.Id == id
                 select new EntryViewModel
                 {
                     Title = en.Title,
                     Username = en.Username,
                     Password = en.Password,
                     Url = en.Url,
                     Description = en.Description,
                     Category = cat.Name
                 }).AsQueryable();

        return View(query);
    }

我收到此错误，无法找到解决方案。

The model item passed into the dictionary is of type
'System.Data.Entity.Infrastructure.DbQuery`1[App.ViewModels.EntryViewModel]',
 but this dictionary requires a model item of type 'App.ViewModels.EntryViewModel'.

查看：

@model PasswordCloudApp.ViewModels.EntryViewModel

@{
ViewBag.Title = "Details";
Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Details</h2>

<fieldset>
<legend>EntryViewModel</legend>

<div class="display-label">
     @Html.DisplayNameFor(model => model.Title)
</div>
<div class="display-field">
    @Html.DisplayFor(model => model.Title)
</div>

<div class="display-label">
     @Html.DisplayNameFor(model => model.Username)
</div>
<div class="display-field">
    @Html.DisplayFor(model => model.Username)
</div>

<div class="display-label">
     @Html.DisplayNameFor(model => model.Password)
</div>
<div class="display-field">
    @Html.DisplayFor(model => model.Password)
</div>

<div class="display-label">
     @Html.DisplayNameFor(model => model.Url)
</div>
<div class="display-field">
    @Html.DisplayFor(model => model.Url)
</div>

<div class="display-label">
     @Html.DisplayNameFor(model => model.Description)
</div>
<div class="display-field">
    @Html.DisplayFor(model => model.Description)
</div>
</fieldset>
<p>
@Html.ActionLink("Edit", "Edit", new { /* id=Model.PrimaryKey */ }) |
@Html.ActionLink("Back to List", "Index")
</p>

有什么建议吗？

Answer 1

您必须在视图中设置模型，如：

@model IQueryable<PasswordCloudApp.ViewModels.EntryViewModel>

Answer 2

您的模型属于PasswordCloudApp.ViewModels.EntryViewModel类型，但您正在从控制器传递IQueryable<EntryViewModel>。

由于您希望给定一个id的单个项目，您可以更改您的控制器代码以返回该单个项目（如果找不到则可能返回404）：

public ActionResult Details(int id)
{

    EntryViewModel model = (from cat in _db.Categories
                            join en in _db.Entries on cat.Id equals en.CategoryId
                            where en.Id == id
                            select new EntryViewModel
                            {
                                Title = en.Title,
                                Username = en.Username,
                                Password = en.Password,
                                Url = en.Url,
                                Description = en.Description,
                                Category = cat.Name
                            }).FirstOrDefault();

    if (model == null) return HttpNotFound();

    return View(model);
}

Answer 3

实际上你有PasswordCloudApp.ViewModels.EntryViewModel绑定到你的视图但是你传递了Iqueryable，所以当你从动作返回视图时，你要关联结果的FirstOrDefault（）或更改视图中的@model IQueryable<PasswordCloudApp.ViewModels.EntryViewModel>。

public ActionResult Details(int id)
    {

        IQueryable<EntryViewModel> query = (from cat in _db.Categories
                 join en in _db.Entries on cat.Id equals en.CategoryId
                 where en.Id == id
                 select new EntryViewModel
                 {
                     Title = en.Title,
                     Username = en.Username,
                     Password = en.Password,
                     Url = en.Url,
                     Description = en.Description,
                     Category = cat.Name
                 }).AsQueryable();

        return View(query.FirstOrDefault());
    }

如何在View MVC4中的Details Action中显示相关表中的数据？

3 个答案: