How to set focus to a control in the dialog startup

Setting focus to a dialog control is more than just call SetFocus.

Normally, the focus is set to a control which was higher in z-order. But we can set focus in two ways.

1. Call SetFocus() function to desired control in OnInitDialog and return FALSE.
2. Call ::PostMessage( this->m_hWnd, WM_NEXTDLGCTL, (WPARAM)( GetDlgItem( IDC_BUTTON1 )->m_hWnd ), TRUE );  in OnInitDialog() and return TRUE. Don’t call SendMessage instead of PostMessage.