Coloring scrollbar with DrawThemeBackground

[_Flaviu]

I am struggling for some while to coloring a control scrollbar, with DrawThemeBackground. (any control, no matter what) ... here is the trial:

void CMyControl::OnDraw(CDC* pDC)
{
// draw control
HTHEME hTheme = OpenThemeData(m_hWnd, L"WINDOW");
// HTHEME hTheme = OpenThemeData(m_hWnd, L"MFCGridCtrl");
if(NULL != hTheme)
{
if(WS_VSCROLL & GetStyle())
{
SCROLLBARINFO si;
si.cbSize = sizeof(SCROLLBARINFO);
GetScrollBarInfo(OBJID_VSCROLL, &si);
CRect rect(si.rcScrollBar);
pDC->FillSolidRect(&rect, RGB(255, 0, 0));
HRESULT hResult = DrawThemeBackground(hTheme, pDC->GetSafeHdc(), SBP_LOWERTRACKVERT, SCRBS_NORMAL, &rect, NULL);
if(S_OK == hResult)
TRACE("ok\n");
else
TRACE("not ok !\n");
}
CloseThemeData(hTheme);
}
}

And I always get not ok ! ... What I'am doing wrong here ? The scrollbar rectangle are ok, I verified ... can you help me ? Thank you.

[Jochen Arndt]

Print the HRESULT code upon failure. It may help to identify the error source (e.g. by printing the corresponding error message using FormatMessage or searching for the code in WinError.h).

[CPallini]

I would check the exact value of hResult, however the documentation page is not encouraging (see the comment at the bottom of the page)[^].

[_Flaviu]

I cheked:

E_FAIL Unspecified failure 0x80004005

I am stuck :( P.S. But I would try FormatMessage too ...

[Jochen Arndt]

Flaviu2 wrote:

But I would try FormatMessage too

That would not help because it will print something similar ("Unspecified error") in the current Windows system language. I'm sorry, but I have no other ideas.

[_Flaviu]

Thank you for your interest, it's weird that I haven't see any example of how to use DrawThemeBackground function ...

[_Flaviu]

I have checked for the first time, but I formatted as int (%d), that's why I saw noise there, not real error returned ... so tricky this DrawThemeBackground function ...

[_Flaviu]

I have tried also:

HTHEME hTheme = OpenThemeData(m\_hWnd, L"SCROLLBAR");

// HTHEME hTheme = OpenThemeData(m_hWnd, L"WINDOW");
// HTHEME hTheme = OpenThemeData(m_hWnd, L"MFCGridCtrl");
if(NULL != hTheme)
{
if(WS_VSCROLL & GetStyle())
{
SCROLLBARINFO si;
si.cbSize = sizeof(SCROLLBARINFO);
GetScrollBarInfo(OBJID_VSCROLL, &si);
CRect rect(si.rcScrollBar);
pDC->FillSolidRect(&rect, RGB(255, 255, 0));
HRESULT hRes = DrawThemeBackground(
hTheme,
pDC->GetSafeHdc(),
SBP_UPPERTRACKVERT,
SCRBS_NORMAL,
&rect,
NULL);
TRACE("HRESULT: %d|%d: OK ? %d\n", hRes, S_OK, hRes == S_OK);
}
CloseThemeData(hTheme);
}

And the result are S_OK now, which is good, however, I have seen nothing colored ... strange ...