I have a function that is currently wrapped up in a Class so I can pass a
variable to it.

This function is going to be threaded out and I would like the class
function to be able to update a control on my form.  (Treeview).

Is this possible and how do I do it?

Here is a simplisitc overview of what I am doing...
Public Class Form1

Public Sub Button1_Click
  GetDirs()
end sub

Public Sub GetDirs()
       Dim dir As String
       Dim i As Integer = 1
       Dim dirs() As String = Directory.GetDirectories("P:\")
       For Each dir In dirs
           Dim t As System.Threading.Thread
           dim oListView as new SubClass1
           t = New System.Threading.Thread(AddressOf
oListView.FileListToListView)
           oListView.sFolder = dir
           '''' I thought by passing the Treeview1 control I could update
it in the class...
           oListView.tView = TreeView1
           t.Start()
           i += 1
           ProgressBar1.Value = 100 * (i / CLng(UBound(dirs)))
       Next
End Sub

end class

Public Class SubClass1
Public sFolder as string
public tView as treeview
public sub FileListToListView
    '''' **** Here is where I want to update the Form1.treeview1 control
    tview.nodes.add(sFolder)
end sub
end class