SetScrollInfo

The SetScrollInfo function sets the parameters of a scroll bar, including the minimum and maximum scrolling positions, the page size, and the position of the scroll box (thumb). The function also redraws the scroll bar, if requested.

int SetScrollInfo(
  HWND hwnd,    // handle to window with scroll bar
  int fnBar,    // scroll bar flag
  LPSCROLLINFO lpsi,
                // pointer to structure with scroll parameters
  BOOL fRedraw  // redraw flag
);
 

Parameters

hwnd

Handle to a scroll bar control or a window with a standard scroll bar, depending on the value of the fnBar parameter.

fnBar

Specifies the type of scroll bar for which to set parameters. This parameter can be one of the following values:

Value	Meaning
SB_CTL	Sets the parameters of a scroll bar control. The hwnd parameter must be the handle to the scroll bar control.
SB_HORZ	Sets the parameters of the given window's standard horizontal scroll bar.
SB_VERT	Sets the parameters of the given window's standard vertical scroll bar.

lpsi

Pointer to a SCROLLINFO structure. Before calling SetScrollInfo, set the cbSize member of the structure to sizeof(SCROLLINFO), set the fMask member to indicate the parameters to set, and specify the new parameter values in the appropriate members.

The fMask member can be a combination of the following values:

Value	Meaning
SIF_DISABLENOSCROLL	Disables the scroll bar instead of removing it, if the scroll bar's new parameters make the scroll bar unnecessary.
SIF_PAGE	Sets the scroll page to the value specified in the nPage member of the SCROLLINFO structure pointed to by lpsi.
SIF_POS	Sets the scroll position to the value specified in the nPos member of the SCROLLINFO structure pointed to by lpsi.
SIF_RANGE	Sets the scroll range to the value specified in the nMin and nMax members of the SCROLLINFO structure pointed to by lpsi.

fRedraw

Specifies whether the scroll bar is redrawn to reflect the changes to the scroll bar. If this parameter is TRUE, the scroll bar is redrawn, otherwise, it is not redrawn.

Return Values

The return value is the current position of the scroll box.

Remarks

The SetScrollInfo function performs range checking on the values specified by the nPage and nPos members of the SCROLLINFO structure. The nPage member must specify a value from 0 to nMax - nMin +1. The nPos member must specify a value between nMin and nMax - max(nPage – 1, 0). If either value is beyond its range, the function sets it to a value that is just within the range.

Windows CE: In Windows CE 2.0, if you pass a null pointer in the lpsi parameter, SetScrollInfo returns zero, rather than the current position of the scroll box.

QuickInfo

  Windows NT: Requires version 3.51 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winuser.h.
  Import Library: Use user32.lib.

See Also

Scroll Bars Overview, Scroll Bar Functions, GetScrollInfo, SCROLLINFO