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 SetScrollRange

The SetScrollRange function sets the minimum and maximum scroll box positions for the specified scroll bar.

Note The SetScrollRange function is provided for backward compatibility. New applications should use the SetScrollInfo function.

Syntax

    BOOL SetScrollRange(  
        HWND hWnd,
        int nBar,
        int nMinPos,
        int nMaxPos,
        BOOL bRedraw
    );

Parameters

• hWnd
  [in] Handle to a scroll bar control or a window with a standard scroll bar, depending on the value of the nBar parameter.
• nBar
  [in] Specifies the scroll bar to be set. This parameter can be one of the following values.
  • SB_CTL
    Sets the range of a scroll bar control. The hwnd parameter must be the handle to the scroll bar control.
  • SB_HORZ
    Sets the range of a window's standard horizontal scroll bar.
  • SB_VERT
    Sets the range of a window's standard vertical scroll bar.
• nMinPos
  [in] Specifies the minimum scrolling position.
• nMaxPos
  [in] Specifies the maximum scrolling position.
• bRedraw
  [in] Specifies whether the scroll bar should be redrawn to reflect the change. If this parameter is TRUE, the scroll bar is redrawn. If it is FALSE, the scroll bar is not redrawn.

Return Value

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

You can use SetScrollRange to hide the scroll bar by setting nMinPos and nMaxPos to the same value. An application should not call the SetScrollRange function to hide a scroll bar while processing a scroll bar message. New applications should use the [ShowScrollBar] function to hide the scroll bar.

If the call to SetScrollRange immediately follows a call to the SetScrollPos function, the bRedraw parameter in SetScrollPos must be zero to prevent the scroll bar from being drawn twice.

The default range for a standard scroll bar is 0 through 100. The default range for a scroll bar control is empty (both the nMinPos and nMaxPos parameter values are zero). The difference between the values specified by the nMinPos and nMaxPos parameters must not be greater than the value of MAXLONG.

Because the messages that indicate scroll bar position, WM_HSCROLL and WM_VSCROLL, are limited to 16 bits of position data, applications that rely solely on those messages for position data have a practical maximum value of 65,535 for the SetScrollRange function's nMaxPos parameter.

However, because the SetScrollInfo, SetScrollPos, SetScrollRange, GetScrollInfo, GetScrollPos, and [GetScrollRange] functions support 32-bit scroll bar position data, there is a way to circumvent the 16-bit barrier of the WM_HSCROLL and WM_VSCROLL messages. See GetScrollInfo for a description of the technique.

If the nBar parameter is SB_CTL and the window specified by the hWnd parameter is not a system scroll bar control, the system sends the SBM_SETRANGE message to the window to set scroll bar information. This allows SetScrollRange to operate on a custom control that mimics a scroll bar. If the window does not handle the SBM_SETRANGE message, the SetScrollRange function fails.

Function Information

• Minimum DLL Version user32.dll
• Header Declared in Winuser.h, include Windows.h
• Import library User32.lib
• Minimum operating systems Windows 95, Windows NT 3.1

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Notebook exported on Monday, 7 July 2008, 18:56:50 PM Eastern Daylight Time