如何修复传入字典的模型项的类型错误?

I am trying to run my first ASP.NET MVC application. I created a cotroller and view. Data is taken from Database. However, when project can run but when I try to navigate Customer page I get following error.

我正在尝试运行我的第一个ASP。净MVC应用程序。我创建了一个分配器和视图。数据取自数据库。但是，当项目可以运行时，当我试图浏览客户页面时，会出现以下错误。

The model item passed into the dictionary is of type 'System.Collections.Generic.List`1[MvcApplication3.Models.Customer]', but this dictionary requires a model item of type 'MvcApplication3.Models.Customer'.

传入字典的模型项是type 'System.Collections.Generic.List ' 1[MvcApplication3.Models]。但是本字典需要一个“MvcApplication3.Models.Customer”类型的模型项。

I am bit confused here, as error says it has requesting model type.

这里我有点困惑，因为error说它有请求模型类型。

Stack trace is

堆栈跟踪是

Stack Trace:

堆栈跟踪:

[InvalidOperationException: The model item passed into the dictionary is of type 'System.Collections.Generic.List1[MvcApplication3.Models.Customer]', but this dictionary requires a model item of type 'MvcApplication3.Models.Customer'.]
System.Web.Mvc.ViewDataDictionary1.SetModel(Object value) +585211
System.Web.Mvc.ViewDataDictionary..ctor(ViewDataDictionary dictionary) +371 System.Web.Mvc.ViewPage1.SetViewData(ViewDataDictionary viewData) +48 System.Web.Mvc.WebFormView.RenderViewPage(ViewContext context, ViewPage page) +73
System.Web.Mvc.WebFormView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +38
System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +115
System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +295 System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +13
System.Web.Mvc.<>c__DisplayClass1a.<InvokeActionResultWithFilters>b__17() +23 System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func1 continuation) +242
System.Web.Mvc.<>c_DisplayClass1c.b_19() +21 System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList1 filters, ActionResult actionResult) +177
System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +89 System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +102 System.Web.Mvc.Async.WrappedAsyncResult1.End() +57 System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +43
System.Web.Mvc.<>c_DisplayClass1d.b_18(IAsyncResult asyncResult) +14
System.Web.Mvc.Async.<>c_DisplayClass4.b_3(IAsyncResult ar) +23 System.Web.Mvc.Async.WrappedAsyncResult1.End() +62
System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +57 System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23 System.Web.Mvc.Async.WrappedAsyncResult1.End() +62
System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +47
System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
System.Web.Mvc.<>c_DisplayClass8.b_3(IAsyncResult asyncResult) +25
System.Web.Mvc.Async.<>c_DisplayClass4.b_3(IAsyncResult ar) +23 System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +47 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9514812 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

[InvalidOperationException]:传入字典的模型项属于“System.Collections.Generic.List1 . MvcApplication3.Models”。但是本字典需要一个“MvcApplication3.Models.Customer”类型的模型项。System.Web.Mvc.ViewDataDictionary1。SetModel(对象值)+ 585211 System.Web.Mvc.ViewDataDictionary . .男星(ViewDataDictionary字典)+ 371 System.Web.Mvc.ViewPage1。SetViewData(ViewDataDictionary视讯系统)+ 48 System.Web.Mvc.WebFormView。RenderViewPage(ViewContext context, ViewPage page) +73 System.Web.Mvc.WebFormView。RenderView(ViewContext ViewContext ViewContext、TextWriter writer、对象实例)+38 System.Web.Mvc.BuildManagerCompiledView。渲染(ViewContext ViewContext ViewContext, TextWriter writer) +115 System.Web.Mvc.ViewResultBase。+ 295 System.Web.Mvc.ControllerActionInvoker ExecuteResult(ControllerContext上下文)。 c__DisplayClass1a.< invokeactionresultwithfilter >b__17() +23 System.Web.Mvc.ControllerActionInvoker。InvokeActionResultFilter(IResultFilter, ResultExecutingContext preContext, Func1 continuation) +242 System.Web.Mvc.<>c_DisplayClass1c.b_19() +21 System.Web.Mvc.ControllerActionInvoker。invokeactionresultfilter (ControllerContext ControllerContext ControllerContext, IList1过滤器，ActionResult) +177 system . web . web . mvc . async .<>c__DisplayClass2a. b__20() +89 system . web.bbvc . async .< bb2 c__DisplayClass25。[endnoteref: 1] [endnoteref: 1] [endnoteref: 1] [endnoteref: 1] [endnoteref: 1] [endnoteref: 1]]。EndInvokeAction(IAsyncResult asyncResult)+ 43 System.Web.Mvc。< > c_DisplayClass1d。b_18(IAsyncResult asyncResult)+ 14 System.Web.Mvc.Async。< > c_DisplayClass4。b_3(IAsyncResult ar) +23 System.Web.Mvc.Async.WrappedAsyncResult1.End() +62 System.Web.Mvc.Controller。EndExecuteCore(IAsyncResult asyncResult)+ 57 System.Web.Mvc.Async。< > c__DisplayClass4。 b__3(IAsyncResult ar) +23 System.Web.Mvc.Async.WrappedAsyncResult1.End() +62 System.Web.Mvc.Controller。EndExecute(IAsyncResult asyncResult)+ 47 System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController。EndExecute(IAsyncResult asyncResult)+ 10 System.Web.Mvc。< > c_DisplayClass8。b_3(IAsyncResult asyncResult)+ 25 System.Web.Mvc.Async。< > c_DisplayClass4。b_3(IAsyncResult ar) +23 system . web.mvc.asyncresult ' 1.End() +62 System.Web.Mvc.MvcHandler。EndProcessRequest(IAsyncResult asyncResult)+ 47 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler。EndProcessRequest(IAsyncResult result) +9 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9514812 System.Web.HttpApplication。ExecuteStep(IExecutionStep, boolean&completedsync) +155。

Here is my controller code.

这是我的控制器代码。

namespace MvcApplication3.Controllers
{
    public class CustomerController : Controller
    {
        //
        // GET: /Customer/

        public ActionResult Index()
        {
            Models.NorthwindDataContext nwd = new Models.NorthwindDataContext();
            return View(nwd.Customers.ToList());
        }

    }
}

Here is the view

这是视图

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<MvcApplication3.Models.Customer>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Index
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

<h2>Index</h2>

</asp:Content>

<asp:Content ID="Content3" ContentPlaceHolderID="FeaturedContent" runat="server">
</asp:Content>

<asp:Content ID="Content4" ContentPlaceHolderID="ScriptsSection" runat="server">
</asp:Content>

Can anybody give me a hint to fix it?

有人能给我点提示吗?

5 个解决方案

#1

You're trying to pass a collection to a view that's designed for a single object.

您试图将集合传递给为单个对象设计的视图。

change your view declaration to

将视图声明更改为。

Inherits="System.Web.Mvc.ViewPage<IEnumerable<MvcApplication3.Models.Customer>>

继承= " System.Web.Mvc.ViewPage < IEnumerable < MvcApplication3.Models.Customer > >

#2

What exactly confuses you? In your aspx file you've defined the model as a customer, yet you pass a list instead to it.

混淆了你什么?在您的aspx文件中，您已经将模型定义为客户，但是您将一个列表传递给它。

Expected model:

预计模型:

System.Web.Mvc.ViewPage<MvcApplication3.Models.Customer>

Your data:

你的数据:

return View(nwd.Customers.ToList());

Obviously a mismatch.

显然不匹配。

#3

In your related view (i.e. the .cshtml file) look for the @model declaration: the ActionResult needs to return the right instance of the model class, e.g. if you have defined

在您的相关视图(即.cshtml文件)中查找@model声明:ActionResult需要返回模型类的正确实例，例如，如果您已经定义了

@model Customer

then your ActionResult needs to be of type Customer. You want to return a list, hence you need to define

那么您的ActionResult需要是Customer类型。您希望返回一个列表，因此需要定义

@model IEnumerable<Customer>

in the view.

在视图中。

#4

The model item passed into the dictionary is of type

传入字典的模型项是类型的

System.Collections.Generic.List1[MvcApplication3.Models.Customer]

but this dictionary requires a model item of type

但是这本字典需要一个类型的模型项

MvcApplication3.Models.Customer

Type mismatch.

类型不匹配。

#5

I had this issue and it was a problem of the model of the view. I had this code in my MVC project:

我有这个问题，它是视图模型的问题。我在MVC项目中有这样的代码:

var config = new MapperConfiguration(cfg =>
        {
            cfg.CreateMap<Author, AuthorViewModel>();
        });

        IMapper mapper = config.CreateMapper();
        var dest = mapper.Map<Author, AuthorViewModel>(author);

        return View("Form", dest);

but the View Form.cshtml had the wrong model:

但是视图的形式。cshtml有错误的模型:

@model ORMVC.Models.Author

So I changed it to:

所以我把它改成:

@model ORMVC.ViewModels.AuthorViewModel