title: Textbox doesn't get updated while threading
body: <p>Here is a sub code inside a module named "Blahing":</p>
  
  <pre><code>    Sub BlahBlah(ByVal Count As Long)
          For i As Long = 0 To Count
              frmBlaher.txtBlah.Appendtext("Blah")
          Next
      End Sub
  </code></pre>
  
  <p>Here is a button click event code inside a form called frmBlaher:</p>
  
  <pre><code>     Private Sub WriteBlah_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles WriteBlah.Click
           Dim Thread As New Threading.Thread(Sub() Blahing.BlahBlah(Val(_
                TxtBlahCount.Text)))
  
           Thread.Start()
       End Sub
  </code></pre>
  
  <p>When I type any number in txtBlahCount (for example 10) and then press the WriteBlah button, nothing happens. I set multiple breakpoints, and I found that the "Appendtext" part occurs but does not work. I checked the Text_Changed event of the txtBlah and it occur, but the only problem, I don't see any text in txtBlah. I'm new to multithreding. and I read many answers to this question before, but none of them showed an example. Could you help?</p>