Specifies whether the scroll bar is a control or part of a window's nonclient area. If it is part of the nonclient area, nBar also indicates whether the scroll bar is positioned horizontally, vertically, or both. It must be one of the following:
SB_CTL Contains the parameters for a scroll bar control. The m_hWnd data member must be the handle of the scroll bar control.
SB_HORZ Specifies that the window is a horizontal scroll bar.
SB_VERT Specifies that the window is a vertical scroll bar.
A pointer to a SCROLLINFO structure. See the Windows SDK for more information about this structure.
Specifies whether the scroll bar should be redrawn to reflect the new position. If bRedraw is TRUE, the scroll bar is redrawn. If it is FALSE, it is not redrawn. The scroll bar is redrawn by default.
The SCROLLINFO structure contains information about a scroll bar, including the minimum and maximum scrolling positions, the page size, and the position of the scroll box (the thumb). See the SCROLLINFO structure topic in the Windows SDK for more information about changing the structure defaults.
The MFC Windows message handlers that indicate scroll-bar position, CWnd::OnHScroll and CWnd::OnVScroll, provide only 16 bits of position data. GetScrollInfo and SetScrollInfo provide 32 bits of scroll-bar position data. Thus, an application can call GetScrollInfo while processing either CWnd::OnHScroll or CWnd::OnVScroll to obtain 32-bit scroll-bar position data.