Question

我正在学习如何使用ViewModels将信息从视图传递到控制器，反之亦然。我的创建操作，视图和视图模型完美地工作，但我在编辑时遇到问题。我收到错误：

传递到字典中的模型项的类型为“CatVM.Models.Cat＆＃39;”，但此字典需要类型为＆＃39; CatVM.Models.EditCatViewModel＆＃39;的模型项。

这是我的代码：

控制器方法

    // GET: /Cats/Edit/5
    public ActionResult Edit(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        Cat cat = unitOfWork.CatRepository.GetByID(id);
        if (cat == null)
        {
            return HttpNotFound();
        }
        return View(cat);
    }

查看

@model CatVM.Models.EditCatViewModel

@{
    ViewBag.Title = "Edit";
}

<h2>Edit</h2>


@using (Html.BeginForm())
{
@Html.AntiForgeryToken()

<div class="form-horizontal">
    <h4>Cat</h4>
    <hr />
    @Html.ValidationSummary(true)
    @Html.HiddenFor(model => model.ID)

    <div class="form-group">
        @Html.LabelFor(model => model.Name, new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Name)
            @Html.ValidationMessageFor(model => model.Name)
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Color, new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Color)
            @Html.ValidationMessageFor(model => model.Color)
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.FurLength, new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.FurLength)
            @Html.ValidationMessageFor(model => model.FurLength)
        </div>
    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.Size, new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.Size)
            @Html.ValidationMessageFor(model => model.Size)
        </div>
    </div>

    <div class="form-group">
        <div class="col-md-offset-2 col-md-10">
            <input type="submit" value="Save" class="btn btn-default" />
        </div>
    </div>
</div>
}

<div>
@Html.ActionLink("Back to List", "Index")
</div>

@section Scripts {
@Scripts.Render("~/bundles/jqueryval")
}

EditCatViewModel

public class EditCatViewModel
{
    public int ID { get; set; }

    [Required]
    [StringLength(50)]
    public string Name { get; set; }

    [Required]
    [StringLength(50)]
    public string Color { get; set; }

    [Required]
    [StringLength(50)]
    [Display(Name = "Fur Type")]
    public string FurLength { get; set; }

    [StringLength(50)]
    public string Size { get; set; }
}
}

Answer 1

这是因为您从CatRepository.GetByID(id);收到的项目属于Cat，而不是EditCatViewModel。

您可以通过从此对象构建新的viewmodel来绕过此问题：

Cat cat = unitOfWork.CatRepository.GetByID(id);
var viewModel = new EditCatViewModel {
 Name = cat.Name,
 Color = cat.Color,
 FurLength = cat.FurLength,
 Size = cat.Size
};

return View(viewModel);

或者，您可以构建implicit或explicit投射方法或使用AutoMapper之类的地图工具。

Answer 2

您的返回视图应为CatVM.Models.EditCatViewModel类型，现在您返回Cat

返回视图（cat）;

在视图模型中转换模型并将此对象传递回视图

如何将ViewModel传递给ASP.NET MVC 5中的编辑操作

2 个答案: