VB.net Version of GB_NIR parser

[MaxtonSoftware]

Hi All,

Thank for the amazing work you's have done to develop this and you have kept it open source which is cool!

I am trying to reverse engineer the parser for GB_NIR in VB.net!
GB_NIR.py

I have managed to start the parse by making the query to the page to scraping off the details I need to make a post request for the data from ws.soni.ltd.uk/DownloadCentre/aspx/FuelMix but I just cant get a response back with any data! All I get back is the same HTML.

example code:

'setup
Dim btnDownloadCSV = "Download CSV"
Dim IG_CSS_LINKS_ = "ig_res/default/ig_monthcalendar.css|ig_res/default/ig_texteditor.css|ig_res/default/ig_shared.css"
Dim target_date = DateTime.Now().Date()
Dim Month = target_date.Month
Dim Day = target_date.Day
Dim Year = target_date.Year
Dim ig_def_dp_cal_clientState = "|0|15," & Year.ToString & "," & Now.ToString("MM") & "," & Year.ToString & "," & Month.ToString & "," & Day.ToString & "||"
Dim FromDatePicker_clientState = "|0|01" & Year.ToString & "-" & Month.ToString & "-" & Day.ToString & "-0-0-0-0||"
Dim ToDatePicker_clientState = "|0|01" & Year.ToString & "-" & Month.ToString & "-" & Day.ToString & "-0-0-0-0||"

'put request
Dim WebClient = New WebClient()
WebClient.Headers(HttpRequestHeader.Accept) = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"
WebClient.Headers(HttpRequestHeader.UserAgent) = "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:55.0) Gecko/20100101 Firefox/55.0"
WebClient.Headers(HttpRequestHeader.ContentType) = "application/x-www-form-urlencoded"
Dim dataText As String = "{'__VIEWSTATE': " + VIEWSTATE.ToString + ",
                '__VIEWSTATEGENERATOR': " + VIEWSTATEGENERATOR.ToString + ",
                '__EVENTVALIDATION': " + EVENTVALIDATION.ToString + ",
                'FromDatePicker_clientState': " + FromDatePicker_clientState.ToString + ",
                'ToDatePicker_clientState': " + ToDatePicker_clientState.ToString + ",
                'btnDownloadCSV': " + btnDownloadCSV.ToString + ",
                '_ig_def_dp_cal_clientState': " + ig_def_dp_cal_clientState.ToString + ",
                '_IG_CSS_LINKS_': " + IG_CSS_LINKS_.ToString + "
                }"
'decode
Dim byteArray As Byte() = Encoding.ASCII.GetBytes(dataText)
Dim eirgridResponse = WebClient.UploadData("http://ws.soni.ltd.uk/DownloadCentre/aspx/FuelMix.aspx", byteArray)
Dim responce = Encoding.ASCII.GetString(eirgridResponse)

Any pointers would be appreacated.
Thanks,
Richard.