Scenario:
Screen capturing on multi display machines.
Capture screen of secondary monitor [which is the only affected]
Turn off Aero:
DwmEnableComposition(DWM\_EC_DISABLECOMPOSITION)
Create a [new] DC for the secondary monitor via:
m_DC->CreateDC(_T("DISPLAY"), _T("\\.\DISPALY2", NULL, NULL);
Result:
The DC will get an offset which "points" to the wrong part of the virtual display
CPoint DCOffset;
BOOL ok = ::GetDCOrgEx( hDC, &DCOffset );
where DCOffset.x and .y will be != 0
Remarks:
This behavior doesn't happen on Vista
If there is a delay between Aero Off and DC creation it may happen that the DC is correct for a while [== no Offset] but if windows are moved or their z-order is changed the DC will get the offset. Workaround: Create new DC when offset occurs.
affected graphic adapters: Intel GMA 4500 , Nvidia 9600GT