CODEWITHSUNDEEP
c#asp.netasp.net-mvclinq
Matt Beaney
Matt Beaney

Reputation: 41

Cannot implicitly convert linq result into viewmodel list

I'm new to MVC and struggling to implement a ViewModel to query multiple tables. Initially my setup worked perfectly but now having reloaded the project I am getting a compilation error as copied below:

Cannot implicitly convert type 'System.Collections.Generic.List<CATEGORY>' to 'System.Collections.Generic.List<TestProject.Models.CATEGORY>'

ViewModel code:

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

namespace TestProject.Models
{
  public class COMPCATEGORY
  {
    public List<COMP> Comp { get; set; }
    public List<CATEGORY> Category { get; set; }
  }
}

Controller Code:

namespace TestProject.Controllers
{
    public class COMPsController : Controller
    {
        private mattbeaneyEntities1 db = new mattbeaneyEntities1();

        // GET: COMPs
        public ActionResult Index()
        {
          COMPCATEGORY viewModel = new COMPCATEGORY();
          viewModel.Category = db.CATEGORies.ToList();
          viewModel.Comp = db.COMPs.ToList();
          return View(viewModel);
        }

DB Context code:

using System;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;


  public partial class mattbeaneyEntities1 : DbContext
  {
    public mattbeaneyEntities1()
      : base("name=mattbeaneyEntities1")
    {
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
      throw new UnintentionalCodeFirstException();
    }

    public virtual DbSet<CATEGORY> CATEGORies { get; set; }
    public virtual DbSet<COMP> COMPs { get; set; }
  }

Upvotes: 4

Views: 1111

Answers (1)

JDandChips
JDandChips

Reputation: 10100

As the error suggests it is having trouble with two types by the same name, when we were only expecting one. The namespace is our clue here:

Cannot implicitly convert type 'System.Collections.Generic.List<CATEGORY>' to 'System.Collections.Generic.List<TestProject.Models.CATEGORY>'

Usually there are a couple of things I like to check in this case:

Firstly: are there two classes that share the same name and belong to different namespaces? It's quite easy to do as your project grows!

Secondary: has the main project namespace changed? Sometimes due to a bit of refactoring we change the project name and then end up with two .dll files in the bin folder, which hold duplicate of all our classes - delete the old one!

Upvotes: 2

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