Why isn't multiselect list showing selected items? MVC

Question

I moved on and then came back to this, but I am still unable to get it to work.

        var companiesList = subcontractRepository.SubcontractCompanies(Subcontract.subcontract_id);
        IEnumerable<Guid> selectedList = companiesList.Select(a => a.Id);
        Companies = new MultiSelectList(companiesList, "Id", "Name", selectedList);

In SubcontractRepository.cs

    public class SelectCompanyItem
    {
        public string Name { get; set; }
        public Guid Id { get; set; }
    }

    public IEnumerable<SelectCompanyItem> SubcontractCompanies(Guid id)
    {
        return
            from c in db.companies
            select new SelectCompanyItem
            {
                Name = c.company_name,
                Id = c.company_id
            };
    }

View:

        <p>
            <label for="Companies">Company:</label>
            <%= Html.ListBox("Companies", Model.Companies) %>
            <%= Html.ValidationMessage("Companies", "*") %>
        </p>

produced html:

    <p>
        <label for="Companies">Company:</label>
        <select id="Companies" multiple="multiple" name="Companies"><option value="4cf411d0-e111-488b-822f-ea194951cfda">Second Company</option>
        <option value="1c21e613-a668-4817-bf6d-73befb8c9dbd">Test Company</option>
        </select>
    </p>

Answer 1

Here is an ugly work around for now. Set your ViewData with the values you want selected.

ViewData["Companies"] = new string[] { "guid-1", "guid-2" };

I am still trying to debug and see why this is happening. Suprisingly the Unit test for this use case in the MVC project works fine.

Answer 2

I found the solution. The ListBox must have a different name from the MultiSelectList. I renamed the MultiSelectList in my original code, and it works. I don't want to even begin to think about the amount of time I spent on this!