Printer4Lazarus not working
lazarus / 5-Lazarus Extra Components

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asmx · 2024-01-07 12:11

I followed this page (https://wiki.freepascal.org/Using_the_printer)
to write a print test program, but it doesn't work properly.

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
PrintUtil; uses  SysUtils, printers; const  LEFTMARGIN = 100; 
HEADLINE = 'I Printed My Very First Text On ';var  YPos, LineHeight,
VerticalMargin: integer;  SuccessString: string;begin  with Printer
do  try    BeginDoc;    Canvas.Font.Name := 'Courier New';   
Canvas.Font.Size := 10;    Canvas.Font.Color := $0;    LineHeight :=
Round(1.2 * Abs(Canvas.TextHeight('I')));    VerticalMargin := 4 *
LineHeight;    // There we go    YPos := VerticalMargin;   
SuccessString := HEADLINE + DateTimeToStr(Now);   
Canvas.TextOut(LEFTMARGIN, YPos, SuccessString);  finally    EndDoc; 
end; end. 
AccessViolationException is thrown directly when running to BeginDoc.

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wp · 2024-01-07 15:48

The wiki article you are referring to is meant for printing out of a
Lazarus GUI application. You are testing printing, however, in a
console application. The difference is that a console application by-
passes the Lazarus widgetset architecture and does not know about the
LCL. The elemental step to make the LCL available in a consolue
application is to add the unit "Interfaces" to the uses clause. But
then you need another unit: "OSPrinters" to make the printer units of
your operating system available.

So, in total, modify your uses clause as follows, and your application
will work (tested on Windows):
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
PrintUtil; uses  Interfaces,    // <--- ADDED  SysUtils, printers, 
osprinters;    // <--- ADDED  //, printer4lazarus;          // <---
Not needed in "uses", but only in "required packages" of
project const  LEFTMARGIN = 100;  HEADLINE = 'I Printed My Very First
Text On ';var  YPos, LineHeight, VerticalMargin: integer; 
SuccessString: string;begin  with Printer do  try    BeginDoc;   
Canvas.Font.Name := 'Courier New';    Canvas.Font.Size := 10;   
Canvas.Font.Color := $0;    LineHeight := Round(1.2 *
Abs(Canvas.TextHeight('I')));    VerticalMargin := 4 * LineHeight;   
// There we go    YPos := VerticalMargin;    SuccessString := HEADLINE
+ DateTimeToStr(Now);    Canvas.TextOut(LEFTMARGIN, YPos,
SuccessString);  finally    EndDoc;  end; end.

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AlexTP · 2024-01-07 17:20

I added this new info (for me) to wiki:
https://wiki.freepascal.org/Using_the_printer#Printing_from_console_ap
plication

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Thaddy · 2024-01-07 18:10

If you want simple printing from a console app, use the unit printer,
not printers.
It is limited to what was possible in DOS times, but does the job.

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asmx · 2024-01-08 13:07

Quote from: wp on January 07, 2024, 04:48:19 pmThe wiki article you
are referring to is meant for printing out of a Lazarus GUI
application. You are testing printing, however, in a console
application. The difference is that a console application by-passes
the Lazarus widgetset architecture and does not know about the LCL.
The elemental step to make the LCL available in a consolue application
is to add the unit "Interfaces" to the uses clause. But then you need
another unit: "OSPrinters" to make the printer units of your operating
system available.

So, in total, modify your uses clause as follows, and your application
will work (tested on Windows):
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
PrintUtil; uses  Interfaces,    // <--- ADDED  SysUtils, printers, 
osprinters;    // <--- ADDED  //, printer4lazarus;          // <---
Not needed in "uses", but only in "required packages" of
project const  LEFTMARGIN = 100;  HEADLINE = 'I Printed My Very First
Text On ';var  YPos, LineHeight, VerticalMargin: integer; 
SuccessString: string;begin  with Printer do  try    BeginDoc;   
Canvas.Font.Name := 'Courier New';    Canvas.Font.Size := 10;   
Canvas.Font.Color := $0;    LineHeight := Round(1.2 *
Abs(Canvas.TextHeight('I')));    VerticalMargin := 4 * LineHeight;   
// There we go    YPos := VerticalMargin;    SuccessString := HEADLINE
+ DateTimeToStr(Now);    Canvas.TextOut(LEFTMARGIN, YPos,
SuccessString);  finally    EndDoc;  end; end.
Thank you for reply , It worked!

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asmx · 2024-01-08 14:59

Thanks every one!