ViewModel MVC 3

I am new to MVC. I am going through the following tutorial.

I am on the portion where it calls for the following code

[HttpPost]
public ViewResult Edit(UserModel um) 
{

  if (!TryUpdateModel(um)) 
  {
    ViewModel.updateError = "Update Failure";
    return View(um);
  }

  // ToDo: add persistent to DB.
  _usrs.Update(um);
  return View("Details", um);
}

When I attempt to use ViewModel I receive an error:

"The name ViewModel does not exist in the current context."

Intellisense does not sho开发者_如何学Cw ViewModel as an option.

ViewModel does not exist for a mvc 3 controller. I think what you are looking to use instead is the following:

ViewBag.UpdateError = "Update Failure";

Then in your view:

@View.UpdateError

I know this is a bit late, but it may be better practice to use the following:

ModelState.AddModelError("", "Update Failure");

Then, in your view:

@Html.ValidationSummary(true)

Instead of ViewModel.UpdateError = "Update Failure";

Use

ViewBag.UpdateError = "Update Failure";

And In your View, Use this

@ViewBag.UpdateError