Listbox + Background Worker (Cross thread problem)

[HunterTTP]

Alright so I will try and make this as simple a possible. For this example, there is listbox1, and button3.

There are 10 items in listbox1 (A-T).

The user selects 1 item and then clicks Button3.

Button3 Starts the background worker.

BackgroundWorker3 downloads a file using My.Computer.Network.DownloadFile ("google.com/" & ItemSelection)

ItemSelection is "Dim(ed)" in the background worker -> Dim ItemSelection = ListBox1.SelectedItem

So what should happen is, the user selects the Item, The user clicks "go", the background worker attempts to download from (if selection was "A") google.com/A.

But what actually happens is, I get a "cross thread" error about how I cannot reference back to ItemSelection because it is not being used on the thread is was created on.

Example Code-

Imports System.IO
Imports Shell32

Public Class Form1

    Dim Desktop As String = My.Computer.FileSystem.SpecialDirectories.Desktop
    Dim Username As String = Environment.UserName
    Private P As Integer

...

Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click

        BackgroundWorker3.RunWorkerAsync()

    End Sub

...

 Private Sub BackgroundWorker3_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker3.DoWork

            Dim ItemSelection = ListBox1.SelectedItem

            My.Computer.Network.DownloadFile("http://google.com/" & ItemSelection, Desktop)

    End Sub

The Error




Any help would be great!


Hunter