Intermec 6200 Reference Guide

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Once Windows has loaded, printing is accomplished through the standard

printing API.  No special processing by the application is needed. The following

sequence demonstrates the correct method for printing under Windows:

1. Create a device context for the printer.  

GetPrinterDC()

 creates the device

context.

2. Set up the device context with the desired fonts, etc.  Keep in mind that

some fonts cause Windows to print completely in graphics mode, which may

provide less performance than desired.  

SelectObject(...)

 sets the

desired font.

3. Set an abort procedure to handle errors during printing and allow the user

to cancel the print job.  

SetABortProc(...)

 sets an abort procedure.

4. Begin the printing operation by calling

 

StartDoc(...)

 to inform GDI that

every output is to be one job.

5. Begin each page of output by calling 

StartPage(...)

 to allow GDI to begin

sending data to the printer on a pageĆbyĆpage basis.

6. Create the page using standard GDI API like 

TextOut(...)

.  The output

operations, that convert text and other objects into a binary data stream,

contain printerĆspecific escape codes.  This data is spooled" until the entire

page is composed.

7. Use 

EndPage(...)

 to finish off a page.  The entire page is then sent to the

printer.  A form feed is generated to move the paper to the top of the next

page.

8. Use 

EndDoc()

 to complete the printing operation.  

AbortDoc()

 can cancel a

job.  GDI cleans things up.

9. Free the instance of your abort procedure using 

FreeProcInstance(...)

.

See the Windows SDK manual for more information about the API used in the

operations previously described.

Once the drivers are loaded as defined previously, no special processing by the

application is needed.  This makes it possible for offĆtheĆshelf packages to take

advantage of the NPCP protocol.  In this mode, all printerĆrelated errors are

handled by the NPCP driver.  A message is displayed and the user can Cancel or

Retry.  If the user selects Retry, the driver attempts to continue printing.  If the

user selects Cancel, the driver attempts to clean up as best it can.  The standard

Windows API returns a standard error, indicating that a problem occurred.  This

is the application's signal to abort the print job.

This is probably the most common mode of operation.  In this mode, the

application can link to the NPCP driver in the same manner that it would link to

any Windows DLL.  Once linked, the application can use the driver's API to

perform various operations.  The application registers a callback with the driver.

The application needs to perform the following actions to define a new error

handler:

1. Link to driver and obtain PrtService entry point.
2. Call PrtService to enable the driver using PRT_ENABLE (0x0001).