代码语言：javascript
复制LOCAL oForm
oForm = CREATEOBJECT("Tform")
oForm.Show(1)
* end of main
DEFINE CLASS Tform As Form
Width=350
Height=160
BorderStyle=2
MaxButton=.F.
MinButton=.F.
Autocenter=.T.
Caption="Magnifier"
hForm=0
hDC=0
ADD OBJECT chMagnify As CheckBox WITH Value=.F.,;
Left=20, Top=20, Autosize=.T., Caption="Activate Magnifier"
ADD OBJECT chInvert As CheckBox WITH Value=.F.,;
Left=20, Top=56, Autosize=.T., Caption="Invert colors"
ADD OBJECT lbl1 As Label WITH;
Left=190, Top=20, Autosize=.T., Caption="Scale:"
ADD OBJECT cmbScale As ComboBox WITH Style=2,;
Left=240, Top=20, Width=70, Height=21
ADD OBJECT cmdClose As CommandButton WITH Cancel=.T.,;
Left=140, Top=112, Width=70, Height=27, Caption="Close"
PROCEDURE Init
THIS.declare
PROCEDURE Activate
IF THIS.hForm = 0
THIS.hForm = GetFocus()
THIS.hDC = GetDC(THIS.hForm)
ENDIF
PROCEDURE Destroy
IF THIS.hDC <> 0
= ReleaseDC(THIS.hForm, THIS.hDC)
ENDIF
PROCEDURE cmdClose.Click
ThisForm.Release
PROCEDURE cmbScale.Init
WITH THIS
.AddItem("Normal")
.AddItem("x 2")
.AddItem("x 3")
.AddItem("x 4")
.ListIndex=3
ENDWITH
PROCEDURE MouseMove
LPARAMETERS nButton, nShift, nXCoord, nYCoord
THIS.Magnify
PROCEDURE chMagnify.MouseMove
LPARAMETERS nButton, nShift, nXCoord, nYCoord
ThisForm.Magnify
PROCEDURE chInvert.MouseMove
LPARAMETERS nButton, nShift, nXCoord, nYCoord
ThisForm.Magnify
PROCEDURE lbl1.MouseMove
LPARAMETERS nButton, nShift, nXCoord, nYCoord
ThisForm.Magnify
PROCEDURE cmbScale.MouseMove
LPARAMETERS nButton, nShift, nXCoord, nYCoord
ThisForm.Magnify
PROCEDURE cmdClose.MouseMove
LPARAMETERS nButton, nShift, nXCoord, nYCoord
ThisForm.Magnify
PROCEDURE Magnify
#DEFINE SRCCOPY 0xCC0020
#DEFINE NOTSRCCOPY 0x00330008
#DEFINE cnDstWidth 600
#DEFINE cnDstHeight 140
IF THIS.chMagnify.Value
LOCAL cBuffer, nX, nY, hDstWin, hDstDC,;
nMode, nSrcWidth, nSrcHeight, nScale
hDstWin = GetActiveWindow()
hDstDC = GetWindowDC(hDstWin)
cBuffer = REPLICATE(Chr(0), 8)
= GetCursorPos(@cBuffer)
= ScreenToClient(THIS.hForm, @cBuffer)
nX = buf2dword(SUBSTR(cBuffer, 1,4))
nY = buf2dword(SUBSTR(cBuffer, 5,4))
nScale = THIS.cmbScale.ListIndex
nSrcWidth = INT(cnDstWidth/nScale)
nSrcHeight = INT(cnDstHeight/nScale)
nMode = IIF(THIS.chInvert.Value,;
NOTSRCCOPY, SRCCOPY)
= StretchBlt(hDstDC, 10, 100,;
cnDstWidth, cnDstHeight, THIS.hDC,;
nX-nSrcWidth/2, nY-nSrcHeight/2,;
nSrcWidth, nSrcHeight, nMode)
= ReleaseDC(hDstWin, hDstDC)
ENDIF
PROCEDURE declare
DECLARE INTEGER GetActiveWindow IN user32
DECLARE INTEGER GetCursorPos IN user32 STRING @lpPoint
DECLARE INTEGER GetWindowDC IN user32 INTEGER hwnd
DECLARE INTEGER GetDC IN user32 INTEGER hwnd
DECLARE INTEGER GetFocus IN user32
DECLARE INTEGER ReleaseDC IN user32;
INTEGER hWindow, INTEGER hdc
DECLARE INTEGER ScreenToClient IN user32;
INTEGER hWindow, STRING @lpPoint
DECLARE INTEGER StretchBlt IN gdi32;
INTEGER hdcDest, INTEGER nXOriginDest,;
INTEGER nYOriginDest, INTEGER nWidthDest,;
INTEGER nHeightDest, INTEGER hdcSrc,;
INTEGER nXOriginSrc, INTEGER nYOriginSrc,;
INTEGER nWidthSrc, INTEGER nHeightSrc,;
INTEGER dwRop
ENDDEFINE
FUNCTION buf2dword(lcBuffer)
RETURN Asc(SUBSTR(lcBuffer, 1,1)) ;
BitLShift(Asc(SUBSTR(lcBuffer, 2,1)), 8) ;
BitLShift(Asc(SUBSTR(lcBuffer, 3,1)), 16) ;
BitLShift(Asc(SUBSTR(lcBuffer, 4,1)), 24)
