ASP.MVC 2 RTM + ModelState Error at Id property

Question

I have this classes:

public class GroupMetadata
{
    [HiddenInput(DisplayValue = false)]
    public int Id { get; set; }

    [Required]
    public string Name { get; set; }
}

[MetadataType(typeof(GrupoMetadata))]
public partial class Group
{
    public virtual int Id { get; set; }
    public virtual string Name { get; set; }
}

And this action:

[HttpPost]
public ActionResult Edit(Group group)
{
    if (ModelState.IsValid)
    {
        // Logic to save
        return RedirectToAction("Index");
    }

    return View(group);
}

That's my view:

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<Group>" %>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
    <% using (Html.BeginForm()) {%>
        <fieldset>
            <%= Html.EditorForModel() %>
            <p>
                <input type="submit" value="Save" />
            </p>
        </fieldset>
    <% } %>
    <div>
        <%=Html.ActionLink("Back", "Index") %>
    </div>
</asp:Content>

But ModelState is always invalid! As I can see, for MVC validation 0 is invalid, but for me is valid. How can I fix it since, I didn't put any kind of validation in Id property?

UPDATE: I don't know how or why, but renaming Id, in my case to PK, solves this problem.

Do you know if this an issue in my logic/configuration or is an bug or expected behavior?

Thank you

Answer 1

You have a required field, Id. It's required because it's non-nullable. You must either (1) submit it with your form or (2) change your model to make Id nullable or (3) use a different type.

Answer 2

Your problem is that you are using a property named 'id' in your model. Try using a different name and you will see it works. Mvc seems to have a problem with that.

I experienced the exact same issue.

Answer 3

Just before if (ModelState.IsValid) remove Id index using this line ModelState.Remove("Id") this way when MVC team remove this bug, you just need to remove this line code of your projects.