Author: Tomas Rutkauskas

How I can select the printer's papersource through code? How I can read the printer 
default setting papersource in my Delphi program?

Answer:

1   { ... }
2   var
3     aDrvName, aPrtName, aPortName: array[0..127] of Char;
4     aDeviceMode: THandle;
5     PDevMode: ^TDevMode;
6     i: Integer;
7   begin
8     with Printer do
9     begin
10      GetPrinter(aDrvName, aPrtName, aPortName, aDeviceMode);
11      PDevMode := GlobalLock(aDeviceMode);
12      try
13        if PDevMode^.dmPaperSize = DMPAPER_A4 then
14          ShowMessage('A4')
15        else if PDevMode^.dmPaperSize = DMPAPER_A3 then
16          ShowMessage('A3')
17        else
18        begin
19          ShowMessage('Size not supported!' + #13 + 'Resetting papersize to A4');
20          PDevMode^.dmPaperSize := DMPAPER_A4;
21        end;
22      finally
23        GlobalUnlock(aDeviceMode);
24      end;
25    end;
26  end;