VB.net BackgroundWorker UI - vb.net

Question

I am trying to create an app that produces an excel document based on user input. The document can become quite extensive (multiple sheets), so I want to put the creation of the document on a BackgroundWorker and pass the progress to a ProgressBar.
I'm having problems accessing UI controls while creating the document.
How can I access multiple UI controls from a BackgroundWorker?
This is a very basic example of two of the many things that i want to do in the BackgroundWorker:
Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
OpenWorkbook()
Dim Combobox() As ComboBox = {ComboBox1, ComboBox2, ComboBox3, ComboBox4}
With xlWorkBook.Sheets("Cover1")
.Range("E5").Value = TextBox1.Text
.Range("E6").Value = TextBox2.Text
.Range("E7").Value = TextBox3.Text
.Range("E8").Value = TextBox4.Text
For i = 0 To Combobox.Count - 1
.Range("A" & i + 1).Value = Combobox(i).Text
Next
End With
CloseWorkBook()
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
BackgroundWorker1.RunWorkerAsync()
End Sub
I'm not experienced at all and after researching on this subject, I'm still not getting along with the Delegate/Invoke. Any help would be awesome. Thanks in advance.

Answer 1

As pointed out by Heinzi you cant just pass reference to a control into a bgw. instead you pass the values.
Option Strict On
Public Class FormControls
WithEvents Bgw As New ComponentModel.BackgroundWorker With {.WorkerReportsProgress = True}
Public Class BgwArgs
Public TxtBx1Txt As String = FormControls.TextBox1.Text
Public TxtBx2Txt As String = FormControls.TextBox2.Text
Public CmbBx1Txt As String = FormControls.ComboBox1.SelectedText
End Class
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim BgwArgs As New BgwArgs
Bgw.RunWorkerAsync(BgwArgs)
End Sub
Private Sub Bgw_DoWork(sender As Object, e As ComponentModel.DoWorkEventArgs) Handles Bgw.DoWork
Dim BgwArgs As BgwArgs = DirectCast(e.Argument, BgwArgs)
.Range("E5").Value = BgwArgs.TxtBx1Txt 'etc
End Sub
End Class
I assume the OpenWorkbook is a sub that uses interop to create xlWorkBook where you would instead want to do that within the thread also, same with CloseWorkbook all that should be handled in the DoWork event and not in their own separate routines.