How can I get my progress bar to update while running code in vb.net

Question

I have some code I'm trying to run while updating a progress bar but instead it runs my code, then the bar fills. I'm using background worker but I'm guessing I'm doing something wrong. I have Visual Studio 2019. It's telling me it needs more details to post this question, but there isn't much else to post.

       txtBrantTrans.Text = Get_Transaction_Number("Brantford")
       txtCambTrans.Text = Get_Transaction_Number("Cambridge")
       txtParisTrans.Text = Get_Transaction_Number("Paris")
       txtWoodTrans.Text = Get_Transaction_Number("Woodstock")

       txtSite.Text = Format(Get_Last_Transaction_DateTime(" "), "MMM dd, yyyy HH:mm")
       txtSite00.Text = Format(Get_Last_Transaction_DateTime("00"), "MMM dd, yyyy HH:mm")
       txtSite01.Text = Format(Get_Last_Transaction_DateTime("01"), "MMM dd, yyyy HH:mm")
       txtSite02.Text = Format(Get_Last_Transaction_DateTime("02"), "MMM dd, yyyy HH:mm")
       txtSite03.Text = Format(Get_Last_Transaction_DateTime("03"), "MMM dd, yyyy HH:mm")
       txtSite04.Text = Format(Get_Last_Transaction_DateTime("04"), "MMM dd, yyyy HH:mm")
       txtSite05.Text = Format(Get_Last_Transaction_DateTime("05"), "MMM dd, yyyy HH:mm")
       txtSite06.Text = Format(Get_Last_Transaction_DateTime("06"), "MMM dd, yyyy HH:mm")
       txtSite07.Text = Format(Get_Last_Transaction_DateTime("07"), "MMM dd, yyyy HH:mm")
       txtSite08.Text = Format(Get_Last_Transaction_DateTime("08"), "MMM dd, yyyy HH:mm")
       txtSite09.Text = Format(Get_Last_Transaction_DateTime("09"), "MMM dd, yyyy HH:mm")
       txtSite10.Text = Format(Get_Last_Transaction_DateTime("10"), "MMM dd, yyyy HH:mm")
       txtSite12.Text = Format(Get_Last_Transaction_DateTime("12"), "MMM dd, yyyy HH:mm")
       txtSite14.Text = Format(Get_Last_Transaction_DateTime("14"), "MMM dd, yyyy HH:mm")
       txtSite15.Text = Format(Get_Last_Transaction_DateTime("15"), "MMM dd, yyyy HH:mm")
       txtSite16.Text = Format(Get_Last_Transaction_DateTime("16"), "MMM dd, yyyy HH:mm")
       txtSite17.Text = Format(Get_Last_Transaction_DateTime("17"), "MMM dd, yyyy HH:mm")


       Change_Colour(txtSite)
       Change_Colour(txtSite00)
       Change_Colour(txtSite01)
       Change_Colour(txtSite02)
       Change_Colour(txtSite03)
       Change_Colour(txtSite04)
       Change_Colour(txtSite05)
       Change_Colour(txtSite06)
       Change_Colour(txtSite07)
       Change_Colour(txtSite08)
       Change_Colour(txtSite09)
       Change_Colour(txtSite10)
       Change_Colour(txtSite12)
       Change_Colour(txtSite14)
       Change_Colour(txtSite15)
       Change_Colour(txtSite16)
       Change_Colour(txtSite17)
   End Sub

Private Sub btnRefresh_Click(sender As Object, e As EventArgs) Handles btnRefresh.Click
       'Fill_Form()
       bgwFillInfo.WorkerReportsProgress = True
       bgwFillInfo.RunWorkerAsync()
   End Sub

   Private Sub bgwFillInfo_DoWork(sender As Object, e As DoWorkEventArgs) Handles bgwFillInfo.DoWork
       Me.Invoke(Sub() Fill_Form())
       For i As Integer = 0 To 10000
           If i Mod 1000 Then
               bgwFillInfo.ReportProgress(i / 100)
           End If
       Next
   End Sub

   Private Sub bgwFillInfo_ProgressChanged(sender As Object, e As ProgressChangedEventArgs) Handles bgwFillInfo.ProgressChanged
       pbFillInfo.Value = e.ProgressPercentage
   End Sub```

Answer 1

With JM's help I was able to get it working amazingly. Here is my code for anyone who wants an example

My refresh button does this but you could also do this on form load

Private Sub btnRefresh_Click(sender As Object, e As EventArgs) Handles btnRefresh.Click
        bgwFillInfo.WorkerReportsProgress = True
        bgwFillInfo.RunWorkerAsync()
    End Sub

Then the DoWork of the BackGroundWork is this

Private Sub bgwFillInfo_DoWork(sender As Object, e As DoWorkEventArgs) Handles bgwFillInfo.DoWork
        Dim textBoxes() As TextBox = {txtBrantTrans, txtCambTrans, txtParisTrans, txtWoodTrans, txtSite, txtSite00, txtSite01, txtSite02, txtSite03, txtSite04, txtSite05, txtSite06, txtSite07, txtSite08, txtSite09, txtSite10, txtSite12, txtSite14, txtSite15, txtSite16, txtSite17}
        Dim locname As String = ""
        Dim data As String = ""
        For i = 0 To textBoxes.GetUpperBound(0)
            Dim progress = (i + 1) * 100 \ textBoxes.Length
            Select Case textBoxes(i).Name
                Case "txtBrantTrans"
                    data = Get_Transaction_Number("Brantford").ToString
                Case "txtCambTrans"
                    data = Get_Transaction_Number("Cambridge").ToString
                Case "txtParisTrans"
                    data = Get_Transaction_Number("Paris").ToString
                Case "txtWoodTrans"
                    data = Get_Transaction_Number("Woodstock").ToString
                Case "txtSite"
                    data = Format(Get_Last_Transaction_DateTime(" "), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite00"
                    data = Format(Get_Last_Transaction_DateTime("00"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite01"
                    data = Format(Get_Last_Transaction_DateTime("01"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite02"
                    data = Format(Get_Last_Transaction_DateTime("02"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite03"
                    data = Format(Get_Last_Transaction_DateTime("03"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite04"
                    data = Format(Get_Last_Transaction_DateTime("04"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite05"
                    data = Format(Get_Last_Transaction_DateTime("05"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite06"
                    data = Format(Get_Last_Transaction_DateTime("06"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite07"
                    data = Format(Get_Last_Transaction_DateTime("07"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite08"
                    data = Format(Get_Last_Transaction_DateTime("08"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite09"
                    data = Format(Get_Last_Transaction_DateTime("09"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite10"
                    data = Format(Get_Last_Transaction_DateTime("10"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite12"
                    data = Format(Get_Last_Transaction_DateTime("12"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite14"
                    data = Format(Get_Last_Transaction_DateTime("14"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite15"
                    data = Format(Get_Last_Transaction_DateTime("15"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite16"
                    data = Format(Get_Last_Transaction_DateTime("16"), "MMM dd, yyyy HH:mm").ToString
                Case "txtSite17"
                    data = Format(Get_Last_Transaction_DateTime("17"), "MMM dd, yyyy HH:mm").ToString

            End Select
            Dim packet = Tuple.Create(textBoxes(i), data)

            bgwFillInfo.ReportProgress(progress, packet)
        Next
    End Sub

The ProgressChanged of the BackGroundWork looks like this

Private Sub bgwFillInfo_ProgressChanged(sender As Object, e As ProgressChangedEventArgs) Handles bgwFillInfo.ProgressChanged
        Dim packet = DirectCast(e.UserState, Tuple(Of TextBox, String))
        Dim textBox = packet.Item1
        Dim data = packet.Item2

        textBox.Text = data
        Change_Colour(textBox)

        pbFillInfo.Value = e.ProgressPercentage

    End Sub

Answer 2

Here's an example of how you might update the UI in the ProgressChanged event handler while doing the rest of the work in the DoWork event handler.

DoWork:

Dim textBoxes = {TextBox1, TextBox2, ..., TextBoxN}

For i = 0 To textBoxes.GetUpperBound(0)
    Dim progress = (i + 1) * 100 \ textBoxes.Length
    Dim data = GetData()
    Dim packet = Tuple.Create(textBoxes(i), data)

    BackgroundWorker1.ReportProgress(progress, packet)
Next

ProgressChanged:

Dim packet = DirectCast(e.UserState, Tuple(Of TextBox, String))
Dim textBox = packet.Item1
Dim data = packet.Item2

textBox.Text = data

ProgressBar1.Value = e.ProgressPercentage

You do the work of getting the data on the background thread and then you pass the data, the control to update with that data and the current progress, then you update that control with the data and the ProgressBar on the UI thread. You can package up the control and the data in whatever way you deem appropriate. I've used a Tuple here but you might choose to use an array or your own dedicated type.