GetScrollRange
The GetScrollRange
function retrieves the current minimum and maximum scroll box (thumb) positions
for the specified scroll bar.
For Windows
95, the GetScrollRange function exists for compatibility with operating
system versions earlier than 4.0. With version 4.0 or later, use the GetScrollInfo
function.
BOOL GetScrollRange(
|
HWND hWnd, |
// handle of window
with scroll bar |
|
int nBar, |
// scroll bar flags |
|
LPINT lpMinPos, |
// address of
variable that receives minimum position |
|
LPINT lpMaxPos |
// address of
variable that receives maximum position |
|
); |
|
Parameters
hWnd
Identifies a
scroll bar control or a window with a standard scroll bar, depending on the
value of the nBar parameter.
nBar
Specifies the
scroll bar from which the positions are retrieved. This parameter can be one of
the following values:
|
Value |
Meaning |
|
SB_CTL |
Retrieves
the positions of a scroll bar control. The hWnd parameter must be the
handle of the scroll bar control. |
|
SB_HORZ |
Retrieves
the positions of the window s standard horizontal scroll bar. |
|
SB_VERT |
Retrieves
the positions of the window s standard vertical scroll bar. |
lpMinPos
Points to the
integer variable that receives the minimum position.
lpMaxPos
Points to the
integer variable that receives the maximum position.
Return Values
If the
function succeeds, the return value is nonzero.
If the
function fails, the return value is zero. To get extended error information,
call GetLastError.
Remarks
If the
specified window does not have standard scroll bars or is not a scroll bar control,
the GetScrollRange function copies zero to the lpMinPos and lpMaxPos
parameters.
The default
range for a standard scroll bar is 0 through 100. The default range for a
scroll bar control is empty (both values are zero).
The messages
that indicate scroll bar position, WM_HSCROLL and WM_VSCROLL, are limited to 16
bits of position data. However, because SetScrollPos, SetScrollRange,
GetScrollPos, and GetScrollRange support 32-bit scroll bar
position data, there is a way to circumvent the 16-bit barrier for the
WM_HSCROLL and WM_VSCROLL messages. See the GetScrollPos function for a
description of the technique and its limits.
See Also