class MyTextBox : System.Windows.Forms.TextBox
{
  protected override void WndProc(ref System.Windows.Forms.Message m)
  {
   if (m.Msg != 0x007B && m.Msg != 0x0301 && m.Msg != 0x0302)
   {
    base.WndProc(ref m);
   }
  }
}