How to avoid Titlebar flicker?

[Dang.D.Khanh]

Hi,
In the the my code,from MFC form, I call the ::Setfocus(hwnd) function to focus another windows application only once.
then i setfocus back to my MFC form.

my code like this:

HWND hwnd=getappHwnd(app);
::Setfocus(hwnd);
::Setfocus(this->m_hWnd);

Even though it's very fast but I still see the Title flicker.
Can I disable it without using the UnTitlebar form (by set property border none)?

Thanks you!