Basic Problem with Asp.net MVC UpdateModel(myClass)

Question

In my Controller in a Asp.net MVC 1 app I want to use UpdateModel to populate a variable with POST data in my controller. I've looked at dozens of examples but even the most basic ones seem to fail silently for me.

Here's a very basic example that's just not working. What am I doing wrong?

    public class TestInfo
    {
        public string username;
        public string email;
    }

   public class AdminController : Controller
    {

        public ActionResult TestSubmit()
        {
            var test = new TestInfo();
            UpdateModel(test);//all the properties are still null after this executes  
            //TryUpdateModel(test); //this returns true but fields / properties all null
            return Json(test);
        }


    }


//Form Code that generates the POST data
    <form action="/Admin/TestSubmit" method="post">
        <div>
            <fieldset>
                <legend>Account Information</legend>
                <p>
                    <label for="username">Username:</label>
                    <input id="username" name="username" type="text" value="" />
                </p>
                <p>
                    <label for="email">Email:</label>
                    <input id="email" name="email" type="text" value="" />
                </p>
                <p>
                    <input type="submit" value="Login" />
                </p>

            </fieldset>
        </div>
    </form>

Answer 1

It looks like you're trying to get the controller to update the model based on the form elements. Try this instead:

    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult TestSubmit(TestInfo test)
    {
        UpdateModel(test);
        return Json(test);
    }

In your code, you're creating a new TestModel instead of letting the MVC runtime serialize it from the HttpPost. I've let myself get wrapped around the axel on this also, you're not the only one!

Answer 2

I'm not too familiar with ASP.NET MVC, but shouldn't your TestSubmit method look more like this:

public ActionResult TestSubmit(TestInfo test)
{
  UpdateModel(test);
  return Json(test);
}

Answer 3

make properties of your public field:

    public class TestInfo
    {
        public string username {get;set;}
        public string email{get;set;}
    }

Answer 4

In the controller you should have two methods, one to respond to the GET, the other, if required is for responding to the POST.

So, firstly have a GET method:

public ActionResult Test ()
{
    return View (/* add a TestInfo instance here if you're getting it from somewhere - db etc */);
}

Secondly, you'll need a POST method:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Test (TestInfo test)
{
    return Json (test);
}

Notice that there's no UpdateMethod there, the ModelBinder would have done that for you.