Ciao,
dovrei effettuare il submit di un form utilizzando un web client.
ho provato il seguente codice
codice:
Dim web As New System.Net.WebClient()
  
Public Sub Prova()
        Try
            web.Headers.Add("Content-Type", "application/x-www-form-urlencoded")
            Dim d As Byte() = System.Text.Encoding.ASCII.GetBytes("username=" & Utente & "&password=" & Password)
            Dim res As Byte() = web.UploadData(https://urlaction, "POST", d)
            Dim s As String
            s = System.Text.Encoding.ASCII.GetString(res)
            Console.WriteLine(s)
        Catch ex As Exception
            Debug.Print(ex.Message)
        End Try
       End Sub
oppure
codice:
Dim WebClient As New WebClient()
   
Public Sub Authenticate(username As String, password As String)
        Dim data As New NameValueCollection()
 
        data.Add("username", username)
        data.Add("password", password)
 
        Dim res As Byte() = WebClient.UploadValues(("https://urlaction"), data)
        Dim s As String
        s = System.Text.Encoding.ASCII.GetString(res)
        Console.WriteLine(s)
       End Sub
ma mi stampa sulla console il codice HTML della pagina come se facessi il submit senza indicare nessun valore.

Dove sbaglio?