VB.NET SetAttribute in WebBrowser doens't work - vb.net

Question

I did some research previously, but all the answers do not work.
The "value" attribute exists in the element but does not appear in the webBrowser, nor in the input.
This is my code until then, I need the webBrowser to read an html file, then load your answers or values ​​from your inputs from a database.
PS:
My application is built in real time, there is no webbrowser control on the screen, it is created shortly after reading the html file and only then it is placed inside a panel.
Dim webBrowser As WebBrowser = New WebBrowser
Dim _doc As HtmlDocument
Dim htmlPath As String = "C:\ePrimeCare\Platis\Debug\Protocolos\" +
nomeProtocolo + "_" + idSistema.ToString() + ".html"
webBrowser.ScriptErrorsSuppressed = True
webBrowser.Navigate(htmlPath)
_doc = webBrowser.Document.OpenNew(False)
'webBrowser.DocumentText = IO.File.ReadAllText(htmlPath).ToString()
'webBrowser.Document.OpenNew(False)
'RetornaRespostasAnteriores(idSistema, idFicha, nomeProtocolo, _doc, Convert.ToDateTime(dtVisita))
_doc.Title = nomeProtocolo
_doc.Write(IO.File.ReadAllText(htmlPath).ToString())
Dim carregaRespostas As CarregarRespostaProtocoloHTML = New CarregarRespostaProtocoloHTML
Dim respostas As DataTable = carregaRespostas.BuscarRespostasProtocoloAnterior(idFicha, idSistema, dtVisita)
Dim idopcaoitem As String = 0
Dim idsetitem As String = 0
Dim value As DataRow()
Dim strArr As String()
For Each element As HtmlElement In _doc.GetElementsByTagName("input")
Dim type As String = element.GetAttribute("type")
Select Case type
Case "text"
strArr = element.GetAttribute("id").Split("_") 'For get the two ids
idopcaoitem = strArr(0)
value = respostas.Select(("IDOPCAOITEM = " + idopcaoitem.ToString()))
If value.Length > 0 Then
element.SetAttribute("value", value(0)(2).ToString())'Here i try to set the value, but does not work
End If
Case "radio"
Debug.WriteLine("Input de radio")
Case "checkbox"
Debug.WriteLine("Input de checkbox")
Case "hidden"
Debug.WriteLine("Input de hidden")
Case Else
Debug.WriteLine("Outro input")
End Select
Next
_doc.Write(IO.File.ReadAllText(htmlPath).ToString())
webBrowser.Refresh(WebBrowserRefreshOption.Completely)
webBrowser.Dock = Dock.Fill
pnlMain.Controls.Add(webBrowser)

Answer 1

All your document rewriting and the refresh you do at the end will overwrite any changes you made to it.
'Either of these will revert the document back to its original state.
_doc.Write(IO.File.ReadAllText(htmlPath).ToString())
webBrowser.Refresh(WebBrowserRefreshOption.Completely)
You don't even need to call _doc.Write() as WebBrowser1.Navigate(htmlPath) will work just as fine.
New code:
Dim webBrowser As New WebBrowser 'Shorthand statement.
Dim _doc As HtmlDocument
Dim htmlPath As String = "C:\ePrimeCare\Platis\Debug\Protocolos\" +
nomeProtocolo + "_" + idSistema.ToString() + ".html"
webBrowser.ScriptErrorsSuppressed = True
webBrowser.Navigate(htmlPath)
_doc = webBrowser.Document 'Removed OpenNew().
_doc.Title = nomeProtocolo
Dim carregaRespostas As New CarregarRespostaProtocoloHTML 'Another shorthand statement.
Dim respostas As DataTable = carregaRespostas.BuscarRespostasProtocoloAnterior(idFicha, idSistema, dtVisita)
(...your variables...)
For Each element As HtmlElement In _doc.GetElementsByTagName("input")
(...your code...)
Next
'(Removed _doc.Write() and Refresh() since they will undo all changes)
webBrowser.Dock = Dock.Fill
pnlMain.Controls.Add(webBrowser)