Question

我在这里看到很多这类问题，但答案似乎都指向了我正在做的事情。救命！！！这是代码片段：

在MVC5控制器中，RegistrationController：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using Angular4DotNetMvc.Models.Registration;

namespace Angular4DotNetMvc.Controllers
{
    public class RegistrationController : Controller
    {

        private RegistrationVmBuilder _registrationVmBuilder = new RegistrationVmBuilder();

        // GET: Registration
        public ActionResult Index()
        {
            RegistrationVm registration = _registrationVmBuilder.BuildRegistrationVm();
            return View(registration);
        } // end public ActionResult Index()

    } // end public class RegistrationController : Controller

} // end namespace Angular4DotNetMvc.Controllers

RegistrationVm类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace Angular4DotNetMvc.Models.Registration
{

    /// <summary>
    /// Registration View Model Class
    /// </summary>
    public class RegistrationVm
    {
        public string Courses { get; set; }
        public string Instructors { get; set; }
    } // end public class RegistrationVm

} // end namespace Angular4DotNetMvc.Models.Registration

View，Index.cshtml：

@model Angular4DotNetMvc.Models.Registration.RegistrationVm
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Index</h2>

RegistrationVmBuilder类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using Angular4DotNetMvc.Models.Courses;
using Angular4DotNetMvc.Models.Instructors;

namespace Angular4DotNetMvc.Models.Registration
{

    /// <summary>
    /// Registration View Model Builder Class
    /// </summary>
    public class RegistrationVmBuilder
    {

        /// <summary>
        /// Constructor
        /// </summary>
        /// <returns>A RegistrationVm Instance</returns>
        public RegistrationVm BuildRegistrationVm()
        {
            var registrationVm = new RegistrationVm
            {
                Courses = GetSerializedCourses(),
                Instructors = GetSerializedInstructors()
            };

            return registrationVm;
        } // end public RegistrationVm BuildRegistrationVm()


        /// <summary>
        /// Get Serialized Courses
        /// </summary>
        /// <returns>A JSON string of serialized courses</returns>
        public string GetSerializedCourses()
        {
            var courses = new[]
            {
                new CourseVm {Number = "CREA101", Name = "Care of Magical Creatures", Instructor = "Rubeus Hagrid"},
                new CourseVm {Number = "DARK502", Name = "Defense Against the Dark Arts", Instructor = "Severus Snape"},
                new CourseVm {Number = "TRAN201", Name = "Transfiguration", Instructor = "Minerva McGonagal"}
            };
            var settings = new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() };
            var serializedCourses = JsonConvert.SerializeObject(courses, Formatting.None, settings);
            return serializedCourses;
        } // end public string GetSerializedCourses()

        /// <summary>
        /// Get Serialized Instructors
        /// </summary>
        /// <returns>A JSON string of serialized instructors</returns>
        public string GetSerializedInstructors()
        {
            var instructors = new[]
                {
                    new InstructorVm {Name = "Rubeus Hagrid", Email = "hagrid@hogwarts.com", RoomNumber = 1001},
                    new InstructorVm {Name = "Severus Snape", Email = "snape@hogwarts.com", RoomNumber = 105},
                    new InstructorVm {Name = "Minerva McGonagall", Email = "mcgonagall@hogwarts.com", RoomNumber = 102},
                };
            var settings = new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() };
            var serializedInstructors = JsonConvert.SerializeObject(instructors, Formatting.None, settings);
            return serializedInstructors;
        } // end public string GetSerializedInstructors()

    } // end public class RegistrationVmBuilder

} // end namespace Angular4DotNetMvc.Models.Registration

调用网址时，http:://localhost:3757/Registration我收到以下错误：

传递到字典中的模型项是类型的＆＃39; Angular4DotNetMvc.Models.Registration.RegistrationVm＆＃39;，但是这个 dictionary需要一个类型为＆＃39; System.String＆＃39;。
的模型项

当视图声明System.String并且在控制器中传递该类的实例时，为什么期望RegistrationVm？

感谢。

Answer 1

我发现了问题。它位于/Shared/_Layout.cshtml文件中（未在我上面的源代码清单中显示）。

    @model Angular4DotNetMvc.Models.Registration.RegistrationVm
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Index</h2>

_Layout.cshtml有一个“@model string”语句，它与从RegistrationController传递的模型RegistrationVm类冲突。为了解决这个问题，我创建了另一个共享文件_StrongLayout.cshtml，没有模型，并在Index.cshtml中引用它。这允许从控制器传递任何强类型模型。

获取＆＃34;传递到字典中的模型项的类型为＆＃34; MVC5应用程序中的异常

1 个答案: