To pick up the default printer use the
PrinterSettings (in English) . Example:
var configImpressora = new PrinterSettings();
Note that this way you are using the Windows manager to get this information. And what you need to do to send the data is just the opposite.
Getting the standard printer will not help much because it does not guarantee that the printer that is there is suitable for what you want. And even if you send it to it, it will send to the Windows manager which is just what you DO NOT want to do.
Unless I do not know anything about it, I doubt that part will help you in anything.
As for the second part of the question:
Essentially you need to write directly to the port, usually
COM1 . sending directly to the port you avoid going through the Windows print manager,
Simplified example (does not have the quality that a production code should have):
var impressora = new System.IO.StreamWriter(@"\.\PRN");
impressora.Write((char)15); //inicia negrito na maioria das impressoras matriciais
When I needed to send it to a standard printer, that's basically what I did.
If you need to choose where the printer is on each machine, I'm afraid you should have a local configuration indicating where the printer is. It can be a simple text file, but it can be a local database, the Windows registry or simply allow the user to choose when to print, which can be enough in many cases.
I placed it in Github for future reference .