2008/11/27 | VFP 中打印屏幕(form
类别(数据库学习笔记) | 评论(0) | 阅读(322) | 发表于 17:01

*******************************************
*-- 程序名称:将表单的内容直接打印      --*
*-- 将窗口中的内容以一个位图的形式打印  --*
*-- 程序作者:未知,来源论坛转帖        --*
*-- 使用方法:在表单中执行该程序既可    --*
*           例:在某表单的一个command   --*
*           按纽中执行 do PrintForm.prg --*
*******************************************

*-- 定义常量
#DEFINE LOGPIXELSX           88
#DEFINE LOGPIXELSY           90
#DEFINE PHYSICALOFFSETX     112
#DEFINE PHYSICALOFFSETY     113
#DEFINE SRCCOPY        13369376
#DEFINE DIB_RGB_COLORS        0

*-- 调用本程序段中的子过程
DO decl

*-- 定义变量
PRIVATE pnWidth, pnHeight, lnBitsPerPixel, lnBytesPerScan
STORE 0 TO pnWidth, pnHeight, lnBitsPerPixel, lnBytesPerScan
LOCAL hwnd, hFormDC, hPrnDC, hMemDC, hMemBmp, hSavedBitmap,;
 xOffsPrn, yOffsPrn, xScale, yScale, lcDocInfo, lcBInfo, lpBitsArray

*-- 得到打印机设备的坐标偏移量
hPrnDC = getDefaultPrnDC()  && 没有进行错误检查
xOffsPrn = GetDeviceCaps(hPrnDC, PHYSICALOFFSETX)
yOffsPrn = GetDeviceCaps(hPrnDC, PHYSICALOFFSETY)

*-- 得到屏幕的窗口句柄,及她们的宽度、高度等。
hwnd = GetFocus()  && a window with keyboard focus
hFormDC = GetWindowDC(hwnd)
= getWinRect (hwnd, @pnWidth, @pnHeight)

*-- 根据屏幕和打印机得到缩放值
xScale = GetDeviceCaps(hPrnDC, LOGPIXELSX)/GetDeviceCaps(hFormDC,LOGPIXELSX)
yScale = GetDeviceCaps(hPrnDC, LOGPIXELSY)/GetDeviceCaps(hFormDC,LOGPIXELSY)

*-- 将屏幕的内容创建为位图图象数据
hMemDC = CreateCompatibleDC (hFormDC)
hMemBmp = CreateCompatibleBitmap (hFormDC, pnWidth, pnHeight)
hSavedBitmap = SelectObject(hMemDC, hMemBmp)

*-- 将位图数据从屏幕拷贝到虚拟设备上
= BitBlt (hMemDC, 0,0, pnWidth,pnHeight, hFormDC, 0,0, SRCCOPY)
= SelectObject(hMemDC, hSavedBitmap)

* retrieving bits from the compatible bitmap into a buffer
* as a device-independent bitmap (DIB) with a BitsPerPixel value
* as one of the printer device context
lcBInfo = InitBitmapInfo(hPrnDC)
lpBitsArray = InitBitsArray()
= GetDIBits (hMemDC, hMemBmp, 0, pnHeight,;
 lpBitsArray, @lcBInfo, DIB_RGB_COLORS)

lcDocInfo = Chr(20) + Repli(Chr(0), 19) && DOCINFO struct - 20 bytes
IF StartDoc(hPrnDC, @lcDocInfo) > 0
 = StartPage(hPrnDC)

 = StretchDIBits (hPrnDC, xOffsPrn, yOffsPrn,;
  xOffsPrn + Int(xScale * pnWidth),;
  yOffsPrn + Int(yScale * pnHeight),;
  0,0, pnWidth, pnHeight,;
  lpBitsArray, @lcBInfo, DIB_RGB_COLORS, SRCCOPY)

 = EndPage(hPrnDC)
 = EndDoc(hPrnDC)
ENDIF

*-- 退出时释放系统资源
= GlobalFree(lpBitsArray)
= DeleteObject(hMemBmp)
= DeleteDC(hMemDC)
= DeleteDC(hPrnDC)
= ReleaseDC(hwnd, hFormDC)
RETURN

PROCEDURE  getWinRect (lnHwnd, lnWidth, lnHeight)
 *-- 返回指定句柄的窗口的宽和高
 #DEFINE maxDword  4294967295  && 0xffffffff
 LOCAL lpRect, lnLeft, lnTop, lnRight, lnBottom
 lpRect = REPLI (Chr(0), 16)
 = GetWindowRect (lnHwnd, @lpRect)

 lnRight  = buf2dword(SUBSTR(lpRect,  9,4))
 lnBottom = buf2dword(SUBSTR(lpRect, 13,4))

 lnLeft   = buf2dword(SUBSTR(lpRect,  1,4))
 IF lnLeft > lnRight
  lnLeft = lnLeft - maxDword
 ENDIF
 lnTop    = buf2dword(SUBSTR(lpRect,  5,4))
 IF lnTop > lnBottom
  lnTop = lnTop - maxDword
 ENDIF

 lnWidth = lnRight - lnLeft
 lnHeight = lnBottom - lnTop
 RETURN

FUNCTION  getDefaultPrnDC
 * returns device context for the default printer
 #DEFINE PD_RETURNDC         256
 #DEFINE PD_RETURNDEFAULT   1024
 LOCAL lcStruct, lnFlags
 lnFlags = PD_RETURNDEFAULT + PD_RETURNDC

 * fill PRINTDLG structure
 lcStruct = num2dword(66) + Repli(Chr(0), 16) +;
  num2dword(lnFlags) + Repli(Chr(0), 42)
 IF PrintDlg (@lcStruct) <> 0
  RETURN buf2dword (SUBSTR(lcStruct, 17,4))
 ENDIF
 RETURN  0

FUNCTION  InitBitmapInfo(hTargetDC)
 #DEFINE BI_RGB         0
 #DEFINE RGBQUAD_SIZE   4  && RGBQUAD
 #DEFINE BHDR_SIZE     40  && BITMAPINFOHEADER

 LOCAL lnRgbQuadSize, lcRgbQuad, lcBIHdr

 * use printer BitPerPixel value
 lnBitsPerPixel = 24

 * initializing BitmapInfoHeader structure
 lcBIHdr = num2dword(BHDR_SIZE) +;
  num2dword(pnWidth) + num2dword(pnHeight) +;
  num2word(1) + num2word(lnBitsPerPixel) +;
  num2dword(BI_RGB) + Repli(Chr(0), 20)

 * creating a buffer for the color table
 IF lnBitsPerPixel <= 8
  lnRgbQuadSize = (2^lnBitsPerPixel) * RGBQUAD_SIZE
  lcRgbQuad = Repli(Chr(0), lnRgbQuadSize)
 ELSE
  lcRgbQuad = ""
 ENDIF
 RETURN  lcBIHdr + lcRgbQuad

PROCEDURE  InitBitsArray()
 #DEFINE GMEM_FIXED   0
 LOCAL lnPtr, lnAllocSize

 * making sure the value is DWORD-aligned
 lnBytesPerScan = Int((pnWidth * lnBitsPerPixel)/8)
 IF Mod(lnBytesPerScan, 4) <> 0
  lnBytesPerScan = lnBytesPerScan + 4 - Mod(lnBytesPerScan, 4)
 ENDIF

 lnAllocSize = pnHeight * lnBytesPerScan
 lnPtr = GlobalAlloc (GMEM_FIXED, lnAllocSize)
 = ZeroMemory (lnPtr, lnAllocSize)
 RETURN  lnPtr

FUNCTION  num2word (lnvalue)
 RETURN Chr(MOD(m.lnvalue,256)) + CHR(INT(m.lnvalue/256))

FUNCTION  num2dword (lnvalue)
 #DEFINE m0       256
 #DEFINE m1     65536
 #DEFINE m2  16777216
 LOCAL b0, b1, b2, b3
 b3 = Int(lnvalue/m2)
 b2 = Int((lnvalue - b3*m2)/m1)
 b1 = Int((lnvalue - b3*m2 - b2*m1)/m0)
 b0 = Mod(lnvalue, m0)
 RETURN Chr(b0)+Chr(b1)+Chr(b2)+Chr(b3)

FUNCTION  buf2word (lcBuffer)
 RETURN Asc(SUBSTR(lcBuffer, 1,1)) + ;
  Asc(SUBSTR(lcBuffer, 2,1)) * 256

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   && so many of them declared here
 DECLARE INTEGER GetFocus IN user32
 DECLARE INTEGER EndDoc IN gdi32 INTEGER hdc
 DECLARE INTEGER GetWindowDC IN user32 INTEGER hwnd
 DECLARE INTEGER DeleteObject IN gdi32 INTEGER hObject
 DECLARE INTEGER CreateCompatibleDC IN gdi32 INTEGER hdc
 DECLARE INTEGER ReleaseDC IN user32 INTEGER hwnd, INTEGER hdc
 DECLARE INTEGER GetWindowRect IN user32 INTEGER hwnd, STRING @lpRect
 DECLARE INTEGER GlobalAlloc IN kernel32 INTEGER wFlags, INTEGER dwBytes
 DECLARE INTEGER GetDeviceCaps IN gdi32 INTEGER hdc, INTEGER nIndex
 DECLARE INTEGER SelectObject IN gdi32 INTEGER hdc, INTEGER hObject
 DECLARE INTEGER StartDoc IN gdi32 INTEGER hdc, STRING @ lpdi
 DECLARE INTEGER GlobalFree IN kernel32 INTEGER hMem
 DECLARE INTEGER PrintDlg IN comdlg32 STRING @ lppd
 DECLARE INTEGER DeleteDC IN gdi32 INTEGER hdc
 DECLARE INTEGER StartPage IN gdi32 INTEGER hdc
 DECLARE INTEGER EndPage IN gdi32 INTEGER hdc

 DECLARE RtlZeroMemory IN kernel32 As ZeroMemory;
  INTEGER dest, INTEGER numBytes

 DECLARE INTEGER CreateCompatibleBitmap IN gdi32;
  INTEGER hdc, INTEGER nWidth, INTEGER nHeight

 DECLARE INTEGER BitBlt IN gdi32;
  INTEGER hDestDC, INTEGER x, INTEGER y,;
  INTEGER nWidth, INTEGER nHeight, INTEGER hSrcDC,;
  INTEGER xSrc, INTEGER ySrc, INTEGER dwRop

 DECLARE INTEGER StretchDIBits IN gdi32;
  INTEGER hdc, INTEGER XDest, INTEGER YDest,;
  INTEGER nDestWidth, INTEGER nDestHeight, INTEGER XSrc,;
  INTEGER YSrc, INTEGER nSrcWidth, INTEGER nSrcHeight,;
  INTEGER lpBits, STRING @lpBitsInfo,;
  INTEGER iUsage, INTEGER dwRop

 DECLARE INTEGER GetDIBits IN gdi32;
  INTEGER hdc, INTEGER hbmp, INTEGER uStartScan,;
  INTEGER cScanLines, INTEGER lpvBits, STRING @lpbi,;
  INTEGER uUsage
 RETURN        && decl

 

-1

评论Comments