How to find PaperSize for custom print sizes under Windows NT and later versions by using Windows API functions (304639)

MORE INFORMATION

In Windows 95, you can select the paper size Custom, and then select the page height and width. Under NT-based systems, to print to a custom size, you must select a printer form, which specifies the paper size. To view the different forms that are available on your system, open the Printers window, and click Server Properties on the File menu. You may not be able to directly select all of these from Visual FoxPro.

The number of the form is stored in the report header, under PaperSize in the EXPR field. To view this, USE the report as a table (USE myReport.frx), BROWSE it, and double-click the Memo in the first line of the EXPR field. The default PaperSize can also be displayed with the PRTINFO(2) function.

This code requires Christof Lange's STRUCT.VCX class, which can be downloaded at various sites on the Internet, including the following:

SET PATH TO c:\STRUCT  && Change this to be wherever you unzipped the class.
SET CLASSLIB TO STRUCT.vcx

CLEAR ALL
CLEAR

*!* Windows API call to list printer forms.
DECLARE LONG EnumFormsA IN winspool.drv AS EnumForms ;
   LONG hPrinter, LONG Level, LONG pForm, ;
   LONG cbBuf, LONG @pcbNeeded, ;
   LONG @ pcReturned
   
*!* Windows API call to get a printer handle.
DECLARE LONG OpenPrinterA IN winspool.drv AS OpenPrinter ;
   STRING pPrinterName, LONG @ phPrinter, LONG pDefault

phPrinter = 0 && Define printer handle for pass-by-reference 
*!* If you pass 0 here, rather than a specific printer name as 
*!* pPrinterName, you will get custom forms defined on 
*!* the local computer. To get forms on a network printer, pass 
*!* a UNC printer name (i.e. from GetPrinter() or APrinters()) 
*!* as a string for pPrinterName to OpenPrinter() below. 
pPrinterName = 0 && Use UNC printer name for network printers 
lnRetVal = OpenPrinter(0, @phPrinter, 0)

IF lnRetVal = 0
   MESSAGEBOX("OpenPrinter failed!")
   RETURN
ENDIF

*!* Create structure to hold returned printer forms.
loForms = CREATEOBJECT("clsPrinterForms")

*!* Define variables for pass-by-reference.
lnFormsPtr = loForms.GetPointer(255)
lnBytesNeeded = 0
lnFormCount = 0

*!* lnRetVal will indicate that this next call failed. This is because
*!* it was told to return 0-length information.
*!* The second call should work properly.
lnRetVal = EnumForms(phPrinter, 1, lnFormsPtr, 0, @lnBytesNeeded, ;
   @lnFormCount)
loForms.FreePointer(lnFormsPtr) && clean up memory

*!* Get the proper memory size reserved, and call EnumForms.
lnFormsPtr = loForms.GetPointer(lnBytesNeeded)
lnRetVal = EnumForms(phPrinter, 1, lnFormsPtr, lnBytesNeeded, ;
   @lnBytesNeeded, @lnFormCount)
IF lnRetVal = 0
   MESSAGEBOX("EnumForms call failed")
   loForms.FreePointer(lnFormsPtr) && clean up memory
   RETURN
ENDIF

*!* When you defined the PrinterForms class, you didn't know how many forms
*!* were being returned. Now that you do, you need to redimension the array
*!* property to hold the proper number of forms, and get them ready to hold 
*!* the form information.
DIMENSION loForms.aForms[lnFormCount]
FOR i = 1 TO lnFormCount
   loForms.aForms[i] = CREATEOBJECT("clsFormInfo")
ENDFOR

*!* Take the memory pointer you received, and break it up into the objects you 
*!* defined below.
loForms.SetPointer(lnFormsPtr)

loForms.FreePointer(lnFormsPtr) && clean up memory

FOR i = 1 TO lnFormCount
   loForm = loForms.aForms[i]
   
   *!* i is what you would see in PaperSize in the Expr field, or in 
   *!* the PRTINFO() function. The Size.cx and cy values are in 1000ths
   *!* of a millimeter: there are 25.4 millimeters to an inch.
   ? i, PADR(loForm.pName, 30), loForm.Size.cx / 25400, loForm.Size.cy / 25400
ENDFOR

RETURN

*!* The class properties correspond to the members of the structures,
*!* and cMembers indicates what type of variables are in the return
*!* from the API call. "l:" indicates a long, "o:" indicates 
*!* a structure, and "pz:" indicates a pointer to a null-terminated 
*!* string.
*!* See Struct.vcx documentation for more information about the STRUCT 
*!* class and its settings.
DEFINE CLASS clsPrinterForms AS STRUCT
   DIMENSION aForms[1]
   cMembers = "o:aForms"

   nMemorySize = 100000  && Reserve memory for pointers

   PROCEDURE INIT
      This.aForms[1] = CREATEOBJECT("clsFormInfo")
      DODEFAULT()
   ENDPROC
ENDDEFINE

DEFINE CLASS clsFormInfo AS STRUCT
   nflags = 0
   pName = ""      && form name
   Size = .NULL.   && paper size
   ImageableArea = .NULL.

   cMembers = "l:nflags, pz:pName, o:size, o:imageableArea"

   PROCEDURE INIT
      This.Size  = CREATEOBJECT("clsSizeL")
      This.ImageableArea = CREATEOBJECT("clsRectL")
      DODEFAULT()
   ENDPROC
ENDDEFINE

DEFINE CLASS clsSizeL AS STRUCT
   cx = 0   && paper width
   cy = 0   && paper height

   cMembers = "l:cx, l:cy"
ENDDEFINE

DEFINE CLASS clsRectL AS STRUCT
   nLeft = 0
   nTop = 0
   nRight = 0
   nBottom = 0

   cMembers = "l:nLeft, l:nTop, l:nRight, l:nBottom"
ENDDEFINE
				

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