c# - 为什么多选列表不显示所选项目？ MVC

Question

我继续前进，然后又回到这里，但我仍然无法让它工作。

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

在 SubcontractRepository.cs 中

    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
            };
    }

查看:

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

生成的 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

我找到了解决方案。 ListBox 必须具有与 MultiSelectList 不同的名称。我在我的原始代码中重命名了 MultiSelectList，它可以工作。我什至不想开始思考我为此花费了多少时间!