Checking whether the report is still printing or not and handling printing errors

rbuser

Hi,
How can I check whether the report is still printing or not after call to
the Print method?
The problem is that I need to print several reports in cycle: one after
another, but only one at a time. To do this I need to know whether the
printer is still busy with my previous report before sending the next one. I
also need to respond on any errors in the printing process that might occur
there. So how do I catch errors that might have happened in the printing
process?

Thank you,
MB.

nardmoseley

ReportBuilder and other Windows applications never wait for the printer to
actually print the pages, instead the rendered pages are stored in the
print queue as part of a Windows print job.

ReportBuilder uses Windows API functions to print. This involves starting
and ending a print job. Print jobs are queued by the Windows print queue.
To see this in actiaion, access the Windows Printer Panel and select the
print icon corresponding to your printer. Then select File | Pause Printing.
Now run ReportBuilder reports (or other windows apps) and print multiple
documents to your printer. You will see that nothing ever prints. Next
double-click on the printer icon. This will display the print queued where
you can see the print jobs are queued. Now select File | Pause Printing
again to turn off the pause and the documents will start printing on your
computer.

There is a Report.OnPrintingComplete method that is called when a RB is
finished with a print job. However, normally if you have a loop and are
printing directly to the printer, you can just code something like this:

Report.DeviceType := dtPrinter;
Report.ShowPrintDialog := False;
Report.ShowCancelDialog := False;

Report.Print;

ShowMessage('Report finished);


If you want to get the status of the print jobs on the Windows printer
queue, you will need to consult the Windows API docs.



--
Nard Moseley
Digital Metaphors
http://www.digital-metaphors.com

rbuser

Guess I don't have any other choise than to dig into API documentation.
Thank you very much for your detailed answer.
MB.

P.S.:I was unable to use Report.OnPrintingComplete method. The RB just seems
to ignore the handler in this event.

nardmoseley

Just tried a simple test here using RB 7.03 and the
Report.OnPrintingComplete works properly. Try creating a new application.
Place a TppReport on a form and a button. Implment the the
Report.OnPrintingComplete aned ButtonClick event-handlers as shown below.


uses
ppTypes;

procedure TForm1.ppReport1PrintingComplete(Sender: TObject);
begin
ShowMessage('report printing completed');
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
ppReport1.DeviceType := dtPrinter;
ppReport1.ShowPrintDialog := False;
ppReport1.ShowCancelDialog := False;

ppReport1.Print;
end;



This event only fires when printing to the printer. If you are loading
reports from database or file templates, then you need to assign the
event-handler after loading the report. Whenver you load templates the
event-handler names saved with the template are used.


--
Nard Moseley
Digital Metaphors
http://www.digital-metaphors.com