mvc3 razor dropdownlistfor causing update model to fail - asp.net-mvc-3

Question

I have a problem with the following code. Basically when I call updatemodel it fails but I dont get an inner exception. If i change the drop down to a text box it works.
class:
public class Member
{
[Key]
public int MemberID { get; set; }
[StringLength(50),Required()]
public string Name { get; set; }
[Range(0,120)]
public short Age { get; set; }
[Required(),MaxLength(1)]
public string Gender {get; set;}
[Required()]
public virtual Team Team { get; set; }
}
controller methods:
[HttpGet]
public ActionResult ViewMember(int id)
{
try
{
var m = db.GetMember(id);
var maleItem = new SelectListItem{Text = "Male", Value= "M", Selected=m.Gender == "M"};
var femaleItem = new SelectListItem{Text = "Female", Value="F", Selected=m.Gender == "F"};
List<SelectListItem> items = new List<SelectListItem>();
items.Add(maleItem);
items.Add(femaleItem);
var genders = new SelectList(items, "Value", "Text");
ViewBag.Genders = genders;
return View(m);
}
catch (Exception ex)
{
return View();
}
}
[HttpPost]
public ActionResult ViewMember(Member m)
{
try
{
var member = db.GetMember(m.MemberID);
m.Team = db.GetTeam(member.Team.TeamID);
UpdateModel(member);
db.Save();
return RedirectToAction("ViewMembers", new { id = member.Team.TeamID });
}
catch (Exception ex)
{
return View();
}
}
and finally cshtml code:
#model GreenpowerAdmin.Models.Member
#using GreenpowerAdmin.Helpers
#{
ViewBag.Title = "ViewMember";
}
<h2>ViewMember</h2>
<script src="#Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"> </script>
<script src="#Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>
#using (Html.BeginForm()) {
#Html.ValidationSummary(true)
<fieldset>
<legend>Member</legend>
#Html.HiddenFor(model => model.MemberID)
<div class="editor-label">
#Html.LabelFor(model => model.Name)
</div>
<div class="editor-field">
#Html.EditorFor(model => model.Name)
#Html.ValidationMessageFor(model => model.Name)
</div>
<div class="editor-label">
#Html.LabelFor(model => model.Team.Name)
</div>
<div class="editor-field">
#Html.DisplayFor(model => model.Team.Name)
#Html.ValidationMessageFor(model => model.Team.Name)
</div>
<div class="editor-label">
#Html.LabelFor(model => model.Age)
</div>
<div class="editor-field">
#Html.EditorFor(model => model.Age)
#Html.ValidationMessageFor(model => model.Age)
</div>
<div class="editor-label">
#Html.LabelFor(model => model.Gender)
</div>
<div class="editor-field">
#Html.DropDownList("Gender", ViewBag.Genders as SelectList)
#Html.ValidationMessageFor(model => model.Gender)
</div>
<p>
<input type="submit" value="Save" />
</p>
</fieldset>
}
<div>
#Html.ActionLink("Back to List", "ViewMembers", new { id=Model.Team.TeamID })
</div>
When I click the save button the updatemodel line fails. As said above, it doesn't fail if I use a text box for gender. Does anyone know what is making it fail or how to debug it?

Answer 1

Try declaring the MemberID property as a nullable integer:
[Key]
public int? MemberID { get; set; }