HOWTO: How to Print a Single Line Without Formfeed |
Q124649
The information in this article applies to:
- Microsoft Windows Software Development Kit (SDK) 3.1
SUMMARY
This article shows by example how to have an application print one line at a time without a formfeed. Windows does not inherently provide this ability because it is in direct conflict with the design philosophy of a multitasking operating system.
One method of single-line printing, including sample code, is provided here. This method uses the combination of the raw.drv sample printer driver and the PASSTHROUGH escape, and supports printing over a network. It has the following limitations:
- This method is not conducive to shared printing. If another application prints, it will assume that the printer is currently at the top of a page, which may not be the case if this code is being used.
- This method is only compatible with dot matrix, daisywheel, or other printers capable of printing a single line or single line feed. It will not work with LaserJet printers that must print a page at a time.
MORE INFORMATION
If you are sure no other application will use the same printer, you can have your application print one line at a time to a dot matrix printer without issuing a formfeed. Use the raw.drv sample printer driver and the PASSTHROUGH escape to accomplish this. Follow these steps:
Download raw.drv and place it in the \WINDOWS directory. For additional information about raw.drv, including instructions for download, please see the following article(s) in the Microsoft Knowledge Base:
Q35708 SAMPLE: Raw.exe Sends Binary Data to Printer w/Device Driver
Do not install this driver as the default printer driver. It is a sample driver and is not intended to be used for commercial applications.
Call the PrintLineNow function by using the following code fragment:
// The Abort Procedure for printing (a generic AbortProc) // This procedure needs to listed be in the Exports section // of the .def file BOOL CALLBACK AbortProc( HDC hDC, int Error ) { MSG msg; while(PeekMessage(&msg, NULL, 0, 0, TRUE)) { TranslateMessage(&msg); DispatchMessage(&msg); } return TRUE; } // The function that prints one line without formfeed BOOL PrintLineNow( char *pData, WORD cbBytes ) { #define LINEBUFFER_LENGTH 80 //or dynamically alloc enough space HDC hDC; char pOutput[LINEBUFFER_LENGTH+sizeof(WORD)]; DOCINFO di; ABORTPROC lpfnAbortProc; // Buffer size is LINEBUFFER_LENGTH bytes if( cbBytes > LINEBUFFER_LENGTH ) return FALSE; // Get the DC using the RAW.DRV driver if( (hDC = CreateDC( "RAW", NULL, "LPT1", NULL ) ) == NULL ) return FALSE; // Set up an Abort Procedure if((lpfnAbortProc = MakeProcInstance(AbortProc, hInst)) == NULL) { DeleteDC( hDC ); return FALSE; } if( SetAbortProc( hDC, lpfnAbortProc ) <= 0 ) { DeleteDC( hDC ); FreeProcInstance( lpfnAbortProc ); return FALSE; } // Start a Document di.cbSize = sizeof( DOCINFO ); di.lpszDocName = "MyDoc"; di.lpszOutput = NULL; if( StartDoc( hDC, &di ) <= 0 ) { DeleteDC( hDC ); FreeProcInstance( lpfnAbortProc ); return FALSE; } // The start of a page if( StartPage( hDC ) <= 0 ) { DeleteDC( hDC ); FreeProcInstance( lpfnAbortProc ); return FALSE; } // Put data in the buffer and send to the printer *(WORD *)pOutput = cbBytes; memcpy( &(pOutput[sizeof(WORD)]), pData, cbBytes ); if( Escape( hDC, PASSTHROUGH, 0, pOutput, NULL ) <= 0 ) { DeleteDC( hDC ); FreeProcInstance( lpfnAbortProc ); return FALSE; } // The end of the page if( EndPage( hDC ) < 0 ) { DeleteDC( hDC ); FreeProcInstance( lpfnAbortProc ); return FALSE; } // End the Document if( EndDoc( hDC ) < 0 ) { DeleteDC( hDC ); FreeProcInstance( lpfnAbortProc ); return FALSE; } // Clean up DeleteDC( hDC ); FreeProcInstance( lpfnAbortProc ); return TRUE; // Success }
Additional query words: NEWFRAME FF Mailing Label Form Feed GdiPrn
Keywords : kb16bitonly _IK kbSDKWin16
Issue type : kbhowto
Technology : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK310
Last Reviewed: July 9, 1999 |