Public Class CThreadGen
 
    Public testThread As Threading.Thread
 
    Public Sub StartThread()
        testThread = New Threading.Thread(AddressOf Run)
        testThread.Start()
    End Sub
 
    Private Sub Run()
        Dim threadAlive As Boolean = True
        While threadAlive = True
            Form1.procMsg("TestValue")
        End While
    End Sub
 
End Class

Public Class Form1
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        Dim threadClass As New CThreadGen
        threadClass.StartThread()
    End Sub
 
    Public Sub procMsg(ByVal msg As String)
        Me.txt_output.Text = Me.txt_output.Text & vbCrLf & msg
    End Sub
End Class