private int OpenFileSubClass
    (
        IntPtr hWnd,
        uint uMsg,
        IntPtr wParam,
        IntPtr lParam,
        IntPtr uIdSubclass,
        uint dwRefData
    )
    {
      switch (uMsg)
      {
        case InteropUtil.WM_PARENTNOTIFY:
          {
            unchecked
            {
              var id = lParam.GetDlgCtrlID();

              if (LOW((uint)wParam) == InteropUtil.WM_CREATE && (id == InteropUtil.ID_FileList || id == 0))
              {
                lParam.SetWindowSubclass(m_defViewSubClassDelegate, 0, 0);
              }
            }
            break;
          }
      }
      return hWnd.DefSubclassProc(uMsg, wParam, lParam);
    }