ASP.Net MVC Simple Edit data from default template

Question

when creating a new View and selecting Edit template, the template will create a textbox for the primary key which is not editable.

   <%=Html.TextBox("CompanyID", Model.CompanyID)%>

So, deleting the control from view, will cause the problem: the collection which is post to controller has the CompanyID=0 , so no edit will be done. But if I put back that line of code to view, the CompanyID in posted collection has the proper value. I am doing much like this tutorial: http://www.asp.net/learn/mvc/tutorial-21-vb.aspx , and there ( gray box above "Listing 6 – Controllers\HomeController.vb (Edit methods)" section ) it is saying you can delete the control, but its not working.. any advice?

Updated Ok, for more explain, here goes 2 problems:
problem 1 in this code:

<AcceptVerbs(HttpVerbs.Post)> _
Function Edit(ByVal movieToEdit As Movie) As ActionResult

if you remove the MovieID textbox from view the movieid in movietoedit collection is always zero, so the tutortial from the asp.net website wont work! if I want to delete the movieID from view, I have to pass the ID to my controller like this:

 <AcceptVerbs(HttpVerbs.Post)> _
Function Edit(ByVal ID as integer,ByVal movieToEdit As Movie) As ActionResult

now I can query Model using this ID.. thats no problem, but it takes me some times to figuring out, as I was doing step by step from the website !

Problem 2 So, How to do Edit without using the movieID in view, even in hidden textbox?
I am using this as my controller: ( using Enity framework )

  <AcceptVerbs(HttpVerbs.Post)> _
Function Edit(ByVal id As Integer, ByVal collection As Company) As ActionResult
    If Not ModelState.IsValid Then
        Return View()
    End If

    Try
        Dim c = _db.CompanySet.FirstOrDefault(Function(m) m.CompanyID = id)

        If c Is Nothing Then
            Return RedirectToAction("index")
        End If



        _db.ApplyPropertyChanges(c.EntityKey.EntitySetName, collection)
        _db.SaveChanges()

        Return RedirectToAction("Index")
    Catch ex As Exception
        Throw ex
    End Try
End Function

And if I remove CompanyID from my view ( textbox or hidden field ) it will give me this error from c.EntityKey.EntitySetName:
The ObjectStateManager does not contain an ObjectStateEntry with a reference to an object of type 'Companies.Company'.
and if I add something like

  <%= Html.TextBox("CompanyName", Model.CompanyName) %>

it will work fine .. I am confused!

note: I checked the code more than 10 times, and I wonder if there is anything I am doing wrong or the tutorial is wrong ..

Answer 1

If you are passing the id and updating specific fields through UpdateModel, it should work. You should better post your Edit method to let us see what's going on. Following example may illustrate the process I tried to explain.

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Edit(int id, FormCollection formValues) {

    Page page = repo.GetPage(id); // returns page with specific id
    UpdateModel(page); // updates page with new form values
    repo.Save(); // saving all the changes
    return RedirectToAction("Details", new { id = page.id });

}

Answer 2

The tutorial is right, you shouldn't leave a textbox with the id, I think they are assuming the id is part of your route, like /movies/edit/1. If that's not the case you can add it to the form action using the route collection or add a hidden field in the form.

Adding the id to the route of the edit action:

    <% using (Html.BeginForm("Edit", "Controller", 
              new {id = Model.Id}, FormMethod.Post))
   { %>

Or a hidden field:

 <%=Html.Hidden("CompanyID", Model.CompanyID)%>

Answer 3

Try this way:

<AcceptVerbs(HttpVerbs.Post)> _
Function Edit(<Bind(Exclude:="Id")> ByVal movieToEdit As Movie) As ActionResult

For more information on ASP.Net MVC, see http://asp.net/learn/mvc