UpdateModel not updating my model - asp.net-mvc

Question

I must have something incorrectly setup as I can't get the UpdateModel function to correctly update my model based on information passed in via a FormCollection.
My View looks like:
#model NSLM.Models.Person
#{
ViewBag.Title = "MVC Example";
}
<h2>My MVC Model</h2>
<fieldset>
<legend>Person</legend>
#using(#Html.BeginForm())
{
<p>ID: #Html.TextBox("ID", Model.ID)</p>
<p>Forename: #Html.TextBox("Forename", Model.Forename)</p>
<p>Surname: #Html.TextBox("Surname", Model.Surname)</p>
<input type="submit" value="Submit" />
}
</fieldset>
My model is:
namespace NSLM.Models
{
public class Person
{
public int ID;
public string Forename;
public string Surname;
}
}
and my controller is:
[HttpPost]
public ActionResult Details(FormCollection collection)
{
try
{
// TODO: Add update logic here
Models.Person m = new Models.Person();
// This doesn't work i.e. the model is not updated with the form values
TryUpdateModel(m);
// This does work
int.TryParse(Request.Form["ID"], out m.ID);
m.Forename = Request.Form["Forename"];
m.Surname = Request.Form["Surname"];
return View(m);
}
catch
{
return View();
}
}
as you can see if I manually assign each property it works fine, so what have I not set that would get the model to be updated with the form values?
Thanks,
Mark

Answer 1

Replace fields with properties in your model, i.e.:
namespace NSLM.Models
{
public class Person
{
public int ID {get; set;}
public string Forename {get; set;}
public string Surname {get; set;}
}
}

Answer 2

By the time the call gets to the action method any automatic model binding has already been performed. Try changing the input parameter of your action method to accept a Person instance. In that case the model binder will try to create the instance and populate it from the values passed by your form.

Answer 3

try this :
view :
#model NSLM.Models.Person
#{
ViewBag.Title = "MVC Example";
}
<h2>My MVC Model</h2>
<fieldset>
<legend>Person</legend>
#using(#Html.BeginForm())
{
#Html.HiddenFor(model => model.ID)
<p>Forename: #Html.EditorFor(model => model.Name)
#Html.ValidationMessageFor(model => model.Name)
</p>
<p>Surname: #Html.EditorFor(model => model.Surname)
#Html.ValidationMessageFor(model => model.Surname)
</p>
<input type="submit" value="Submit" />
}
</fieldset>
Controller :
[HttpPost]
public ActionResult Details(Person p)
{
if (ModelState.IsValid)
{
db.Entry(p).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
return View(p);
}