我会尽力直截了当.我在StackOverflow上有一些构建viewmodel的帮助.它在MVC 4中运行良好但现在我将应用程序转换为MVC 5它无法正常工作.代码方式没有任何改变.我有一个_navigation.cshtml,它是在我的Layout.cshtml中呈现的部分,并且错误在该Partial中的For循环内.这个相同的代码在MVC 4中工作正常.这是代码：

我的错误是在for循环期间的部分页面中,我在行中的Ingredient上得到错误：

@foreach (Ingredient ingredient in Model.Ingredients)

也可以在同一个地方的任何其他地方循环.错误说：

The type or namespace name ‘Recipe’ could not be found (are you
missing a using directive or an assembly reference?)

这是我的代码：

型号/ Ingredient.cs

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

    namespace XXX.Models
    {
        public class Ingredient
        {
            public int IngredientID { get; set; }
            public string IngredientNameEs { get; set; }
        }
    }

型号/ Recipe.cs

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

    namespace XXX.Models
    {
        public class Recipe
        {
            public int RecipeID { get; set; }
            public string RecipeNameEs { get; set; }
        }
    }

型号/ IdentityModel.cs

using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations.Schema;
    using System.Data.Entity;
    using System.Data.Entity.ModelConfiguration.Conventions;
    using System.Linq;
    using System.Web;
    using Microsoft.AspNet.Identity.EntityFramework;
    using XXX.Models;

    namespace XXX.Models
    {
        // You can add profile data for the user by adding more properties to your ApplicationUser class,// http://go.microsoft.com/fwlink/?LinkID=317594 for more.
        public class ApplicationUser : IdentityUser
        {
        }

        public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
        {
            public ApplicationDbContext(): base("DefaultConnection")
            {
            }

            public DbSet<Ingredient> Ingredients { get; set; }
            public DbSet<Recipe> Recipes { get; set; }

        }
    }

的viewmodels / Navigationviewmodel.cs

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

    namespace XXX.viewmodels
    {
        public class Navigationviewmodel
        {
            public IEnumerable<Ingredient> Ingredients { get; set; }
            public IEnumerable<Recipe> Recipes { get; set; }
        }
    }

控制器/ PartialsController.cs

using XXX.Models;
    using XXX.viewmodels;
    using System;
    using System.Collections.Generic;
    using System.Data;
    using System.Data.Entity;
    using System.Linq;
    using System.Web;
    using System.Web.Mvc;

    namespace XXX.Controllers
    {
        public class PartialController : Controller
        {
            private ApplicationDbContext db = new ApplicationDbContext();

             public ActionResult Navigation()
             {
             Navigationviewmodel viewmodel;

             viewmodel = new Navigationviewmodel();
             viewmodel.Ingredients = db.Ingredients.Where(i => i.IsProduct != false).ToList();
             viewmodel.Recipes = db.Recipes.ToList();

             return PartialView("_Navigation",viewmodel);
             }
         }
    }

Partials / _Navigation.cshtml(星号表示For Loop中的成分和配方附近的错误)

@model XXX.viewmodels.Navigationviewmodel
@using XXX.Models
//edited for brevity..
   <li class="has-dropdown">@Html.ActionLink(XXX.Views.Shared.CultureSwap.Products,"Products","Ingredient")
        <ul class="dropdown">
            @*//From Navigationviewmodel print out each Product*@
            @foreach (*Ingredient* ingredient in Model.Ingredients)
            {
                <li><a href="/Ingredient/Products/#@ingredient.IngredientNameEs">@ingredient.IngredientNameEs</a></li>
    }
        </ul>
    </li>

    <li class="divider"></li>
    <li class="has-dropdown">@Html.ActionLink(XXX.Views.Shared.CultureSwap.Recipes,"List","Recipe")
        <ul class="dropdown">
            @foreach (*Recipe* recipe in Model.Recipes)
            {
                <li><a href="/Recipe/List/#@recipe.RecipeNameEs">@recipe.RecipeNameEs</a></li>
            }
        </ul>
    </li>

错误再读：

The type or namespace name ‘Ingredient’ could not be found (are you
missing a using directive or an assembly reference?)

The type or namespace name ‘Recipe’ could not be found (are you
missing a using directive or an assembly reference?)

以下是Visual Studio中错误的屏幕截图,在相同代码旁边没有错误：

@model XXX.viewmodels.Navigationviewmodel
@using XXX.Models
...
@foreach (Ingredient ingredient in Model.Ingredients)
{
    ...
}

public class Ingredientviewmodel
{
    ...
}

public class Recipeviewmodel
{
    ...
}

public class Navigationviewmodel
{
    public IEnumerable<Ingredientviewmodel> Ingredients { get; set; }
    public IEnumerable<Recipeviewmodel> Recipes { get; set; }
}

@using XXX.viewmodels
@model Navigationviewmodel

...