DO decl
#DEFINE DCB_RESET       1
#DEFINE DCB_ACCUMULATE  2
#DEFINE DCB_ENABLE      4
#DEFINE DCB_DISABLE     8
#DEFINE DCB_SET       BitOr(DCB_RESET, DCB_ACCUMULATE)
 
LOCAL hWindow, hDC, lcRect, lnResult
 
* retrieving the device context for the main VFP window
hWindow = GetActiveWindow()
hDC = GetWindowDC(hWindow)
 
* allocating a buffer for the RECT structure
lcRect = Repli(Chr(0), 16) && 4 DWORDs
 
* obtaining the current accumulated bounding rectangle 
* for the device context
lnResult = GetBoundsRect (hDC, @lcRect, 0)
 
DO CASE
CASE lnResult = 0
    ? "The specified device context handle is invalid"
CASE lnResult = DCB_DISABLE
    ? "Boundary accumulation is off"
CASE lnResult = DCB_ENABLE
    ? "Boundary accumulation is on"
CASE lnResult = DCB_RESET
    ? "The bounding rectangle is empty"
CASE lnResult = DCB_SET
* The bounding rectangle is not empty
    ? "The bounding rectangle:",;
        buf2dword(SUBSTR(lcRect,  1,4)),;
        buf2dword(SUBSTR(lcRect,  5,4)),;
        buf2dword(SUBSTR(lcRect,  9,4)),;
        buf2dword(SUBSTR(lcRect, 13,4))
ENDCASE
 
= ReleaseDC(hWindow, hDC)
* end of main
 
FUNCTION  buf2dword (lcBuffer)
RETURN Asc(SUBSTR(lcBuffer, 1,1)) + ;
    Asc(SUBSTR(lcBuffer, 2,1)) * 256 +;
    Asc(SUBSTR(lcBuffer, 3,1)) * 65536 +;
    Asc(SUBSTR(lcBuffer, 4,1)) * 16777216
 
PROCEDURE  decl
    DECLARE INTEGER GetActiveWindow IN user32
    DECLARE INTEGER GetWindowDC IN user32 INTEGER hwnd
    DECLARE INTEGER ReleaseDC IN user32 INTEGER hwnd, INTEGER hdc
 
    DECLARE INTEGER GetBoundsRect IN gdi32;
        INTEGER hdc, STRING @lprcBounds, INTEGER flags