SBM_GETSCROLLINFO

  • Article

This message is sent by an application to retrieve the parameters of a scroll bar.

SBM_GETSCROLLINFO wParam = 0; 
  lParam = (LPARAM) (LPSCROLLINFO) lpsi;

Parameters

  • lpsi
    Long pointer to a SCROLLINFO structure. Before sending the message, set the cbSize member of the structure to sizeof(SCROLLINFO), and set the fMask member to specify the scroll bar parameters to retrieve. Before returning, the message copies the specified parameters to the appropriate members of the structure.

    The fMask member can be a combination of the following values

    Value Description
    SIF_ALL Combines SIF_PAGE, SIF_POS, SIF_RANGE, and SIF_TRACKPOS.
    SIF_PAGE Copies the scroll page to the nPage member of the SCROLLINFO structure pointed to by lpsi.
    SIF_POS Copies the scroll position to the nPos member of the SCROLLINFO structure pointed to by lpsi.
    SIF_RANGE Copies the scroll range to the nMin and nMax members of the SCROLLINFO structure pointed to by lpsi.
    SIF_TRACKPOS Copies the current scroll box tracking position to the nTrackPos member of the SCROLLINFO structure pointed to by lpsi.

Return Values

TRUE indicates that the message retrieved at least one value. FALSE indicates otherwise.

Remarks

The messages that indicate scroll-bar position, WM_HSCROLL and WM_VSCROLL, provide only 16 bits of position data. However, the SCROLLINFO structure used by SBM_GETSCROLLINFO, SBM_SETSCROLLINFO, GetScrollInfo, and SetScrollInfo provides 32 bits of scroll-bar position data. You can use these messages and functions while processing either the WM_HSCROLL or WM_VSCROLL messages to obtain 32-bit scroll-bar position data.

To get the 32-bit position of the scroll box (thumb) during a SB_THUMBTRACK message in a WM_HSCROLL or WM_VSCROLL message, send SBM_GETSCROLLINFO with the SIF_TRACKPOS value in the fMask member of the SCROLLINFO structure. The message returns the tracking position of the scroll box in the nTrackPos member of the SCROLLINFO structure. This allows you to get the position of the scroll box as the user moves it. Alternatively, you can use the GetScrollInfo function to get the same information.

Requirements

OS Versions: Windows CE 1.0 and later.
Header: Commctrl.h.

See Also

SBM_SETSCROLLINFO | SCROLLINFO

Last updated on Wednesday, April 13, 2005

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