dynamically add buttons to toolbar

I use control CXTPToolBar and dynamically add buttons:
toolbar->GetControls()->Add(xtpControlButton, ....)
But buttons and not drawn correctly.
I see only a part of the first button.
If my toolbar is floating, it's OK.
But if it is docked (at the top in my case) I have to undock it to see my buttons.

I tried several things but unsuccessfully:

CSize sz = toolbar->CalcDynamicLayout(0, LM_HORZ);
toolbar->SetWindowPos(&CWnd::wndTop, 0, 0, sz.cx, sz.cy, 0);

OR
 toolbar->GetParent()->RepositionBars(AFX_IDW_CON TROLBAR_FIRST, AFX_IDW_CONTROLBAR_LAST, 0);

OR

toolbar->RedrawWindow();
toolbar->UpdateWindow();
toolbar->GetParent()->UpdateWindow();

Just repeat code you have in OnSize, or call dialog OnSize as method

something:

CSize sz = toolbar->CalcDynamicLayout(0, LM_HORZ|LM_COMMIT);
toolbar->SetWindowPos(&CWnd::wndTop, 0, 0, sz.cx, sz.cy, SWP_NOMOVE);