Solved

The model item passed into the dictionary is of type 'System.Collections.Generic.List' but this dictionary requires a model item of type 'System.Collections.Generic.IEnumberable'

Posted on 2014-03-18
3
4,161 Views
Last Modified: 2014-03-23
I have an MVC 4 application that has a model developed using EF 5.0 (Code First).  I am investigating TDD and had to make changes to the code generated by the model in order to get my unit tests to work.  Now that my unit tests work I am getting the following error when I try and run the application.

System.InvalidOperationException: The model item passed into the dictionary is of type 'System.Collections.Generic.List`1[AppCatalog.Models.AppCatalog_Database]', but this dictionary requires a model item of type 'System.Collections.Generic.IEnumerable`1[AppCatalogData.AppCatalog_Database]'.

Open in new window


Here is my controller:
namespace AppCatalog.Controllers
{
    public class DBCatalogController : Controller
    {
        private IAppCatalog db { get; set; }

        public DBCatalogController(IAppCatalog dataContext = null)
        {
            db = dataContext ?? new AppCatalogContainer();
        }
        public DBCatalogController()
        {
            db = new AppCatalogContainer();
        }

        //
        // GET: /DBCatalog/

        public ViewResult Index()
        {
            ViewBag.Title = "Application Catalog -> Database Catalog";

            var appcatalog_database = db.AppCatalog_Database.Include(a => a.AppCatalog_ServerType);
            return View(appcatalog_database.ToList());
        }
   }
}

Open in new window


Here is the model definition in my view:
@model IEnumerable<AppCatalogData.AppCatalog_Database>

Open in new window


Here is my Interface definition:
namespace AppCatalog.Models 
{
    public interface IAppCatalog 
    {
        IDbSet<AppCatalog_Database> AppCatalog_Database { get; set; }
        IDbSet<AppCatalog_ServerType> AppCatalog_ServerType { get; set; }
        IDbSet<AppCatalog_DBConnection> AppCatalog_DBConnection { get; set; }
        IDbSet<AppCatalog_Environment> AppCatalog_Environment { get; set; }
        IDbSet<AppCatalog_PIIData> AppCatalog_PIIData { get; set; }
        IDbSet<AppCatalog_Application> AppCatalog_Application { get; set; }
        IDbSet<AppCatalog_ApplicationTable> AppCatalog_ApplicationTable { get; set; }

        int SaveChanges();
        void Dispose();
    }

Open in new window


Here is the AppCatalogContainer definition:
namespace AppCatalog.Models
{
    using System;
    using System.Data.Entity;
    using System.Data.Entity.Infrastructure;
    
    public partial class AppCatalogContainer : DbContext, IAppCatalog
    {
        public AppCatalogContainer()
            : base("name=AppCatalogContainer")
        {
        }
    
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            throw new UnintentionalCodeFirstException();
        }
    
        public IDbSet<AppCatalog_Database> AppCatalog_Database { get; set; }
        public IDbSet<AppCatalog_ServerType> AppCatalog_ServerType { get; set; }
        public IDbSet<AppCatalog_DBConnection> AppCatalog_DBConnection { get; set; }
        public IDbSet<AppCatalog_Environment> AppCatalog_Environment { get; set; }
        public IDbSet<AppCatalog_PIIData> AppCatalog_PIIData { get; set; }
        public IDbSet<AppCatalog_Application> AppCatalog_Application { get; set; }
        public IDbSet<AppCatalog_ApplicationTable> AppCatalog_ApplicationTable { get; set; }
    }
}

Open in new window


I'm not sure what change I need to make to the View or the Controller to get this to work.  Everything worked fine until I made the changes for the unit testing.

Any help is greatly appreciated!
0
Comment
Question by:dyarosh
  • 2
3 Comments
 
LVL 19

Expert Comment

by:Daniel Van Der Werken
ID: 39937343
Well, it looks like you are returning a List() and it is expecting an IEnumerable<> back.

So, I think these lines of code are the issue:

var appcatalog_database = db.AppCatalog_Database.Include(a => a.AppCatalog_ServerType);
return View(appcatalog_database.ToList());

Open in new window


Instead of doing the .ToList(), do as documented here:
http://msdn.microsoft.com/en-us/library/bb739071(v=vs.110).aspx

I would do:

return View(appcatalog_database.IEnumerable<AppCatalogData.AppCatalog_Database>().GetEnumerator();

Open in new window


...or something like that. I don't have your code, so I can't fiddle with it.
0
 

Accepted Solution

by:
dyarosh earned 0 total points
ID: 39937486
I found the problem.  I had to make sure my model derived from DbContext and my interface (IAppCatalog).
0
 

Author Closing Comment

by:dyarosh
ID: 39948428
I found the problem on my own.
0

Featured Post

How to run any project with ease

Manage projects of all sizes how you want. Great for personal to-do lists, project milestones, team priorities and launch plans.
- Combine task lists, docs, spreadsheets, and chat in one
- View and edit from mobile/offline
- Cut down on emails

Join & Write a Comment

Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
Performance in games development is paramount: every microsecond counts to be able to do everything in less than 33ms (aiming at 16ms). C# foreach statement is one of the worst performance killers, and here I explain why.
Polish reports in Access so they look terrific. Take yourself to another level. Equations, Back Color, Alternate Back Color. Write easy VBA Code. Tighten space to use less pages. Launch report from a menu, considering criteria only when it is filled…
This tutorial demonstrates a quick way of adding group price to multiple Magento products.

747 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

12 Experts available now in Live!

Get 1:1 Help Now