CODEWITHSUNDEEP
asp.netvb.net
Developer
Developer

Reputation: 59

The model isn't passed to the post method of the controller (asp.net visual basic)

I'm trying to pass the model(PresentationModel in my case) as variable to the post method in the controller. However it crashes because my parameter isn't send with it. However this should be optional but it crashes anyway. This is what i got so far.

Model

Public Class ClassA

Public Shared Items As List(Of ClassA) = New List(Of ClassA)

<Required(ErrorMessage:="Required")>
<MinLength(100, ErrorMessage:="to short")>
Public Name As String

<Required(ErrorMessage:="Required")>
Public Age As Integer

Public Message As String

Public Sub New(name As String, age As Integer, message As String)
    Me.Name = name
    Me.Age = age
    Me.Message = message
End Sub

Public Sub AddItem(item As ClassA)
    Items.Add(item)
End Sub
End Class

PresentationModel

Public Class PMClassA
Inherits ClassA

Public Extra As String

Public Sub New(name As String, age As Integer, message As String)
    MyBase.New(name, age, message)
End Sub

End Class

Controller

    <HttpGet>
Function Test() As ActionResult
    Dim v As PMClassA = New PMClassA("test", 0, "test")
    Dim ListItem As List(Of SelectListItem) = New List(Of SelectListItem)

    For i As Integer = 0 To 5
        v.AddItem(New ClassA("Name" + i.ToString(), i, "Message" + i.ToString()))
        ListItem.Add(New SelectListItem With {.Text = PMClassA.Items.Item(i).Name, .Value = PMClassA.Items.Item(i).Name})
    Next i

    ViewBag.Variable = v.Name

    ViewData("List") = New SelectList(ListItem, "Value", "Text", "")

    Return View(v)
End Function

<HttpPost>
Function TestPost(Optional PMClassA As PMClassA = Nothing) As ActionResult
    If (String.IsNullOrEmpty(Request.QueryString("PMClassA")) Or String.IsNullOrEmpty(Request.QueryString("Extra"))) Then
        Return View("Error")
    End If

    If (ModelState.IsValid) Then
        Return View()
    End If

    Return View

View

@ModelType TestApp.PMClassA

<h2>@ViewBag.Variable</h2>

@Using (Html.BeginForm("TestPost", "Home", FormMethod.Post))
@Html.AntiForgeryToken()

@<div class="form-horizontal">
    <h4>ClassA</h4>

     @Html.ValidationMessageFor(Function(model) model.Name)
     <br />
     @Html.ValidationMessageFor(Function(model) model.Age)
     <br />
     @Html.ValidationMessageFor(Function(model) model.Message)

     <input type="hidden" value="extra stuff" name="Extra" />

    <hr />
    @Html.ValidationSummary(True, "", New With {.class = "text-danger"})
     <p>@Html.DropDownListFor(Function(model) model.Name, ViewData("List"))</p>

    <div class="form-group">
        <div class="col-md-offset-2 col-md-10">
            <input type="submit" value="Opslaan" name="Opslaan" class="btn btn-default" />
        </div>
    </div>
</div>
End Using

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

Why do i get in my post method Nothing as value? I should get the PMClassA object with the variables: "Name, Age, Message" from ClassA and "Extra" from PMClassA.

Edit

I can however get the info for Name and Extra.

 Function TestPost(Optional Name As String = "", Optional Extra As String = "") As ActionResult
    If (String.IsNullOrEmpty(Request.QueryString("Name")) Or String.IsNullOrEmpty(Request.QueryString("Extra"))) Then
        Return View("Error")
    End If

However why do i get "Name" and "Extra" and not the PMClassA object with "Name" and "Extra" filled in?

Upvotes: 0

Views: 45

Answers (1)

Mitchel Sellers
Mitchel Sellers

Reputation: 63126

Looking at your code here, it appears that your interface doesn't match the posting requirements, and additionally for the post method you wouldn't need it to be optional in this case as the expectation is that you are in fact getting the desired model back.

A few other observations.

  1. You have a field for "age" marked as required, however, you don't provide an input for it. This will cause an issue as you get things back
  2. You are working with a post, so your attempts in the controller to test for the querystring will most likely not be correct. As the form data is a POST and looking at your form definition it will not have any query parameters

Upvotes: 1

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