>>I'm implementing an ActiveX which will allow text editing within the app, but not exporting texts. The texts can be saved, but will be encrypted and not usable outside the app.
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>>So far so good, no problem expected yet. However, the app must allow printing. I need to detect printing via a driver which actually exports into a reusable file (PostScript, PDF), and prevent it.
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>>Is there a way (API?) to detect which printers may require or offer printing into a file? Or should I just check for usual suspects (anything with PDF, Post Script and Generic/Text in the printer name)?
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>In general I don't think you can do this. For example, you can't prevent someone from installing a 3rd party port redirector and sending a print job anywhere they like.

Those among the expected user population who know how to do that are the 1% that would break anything - and they are of no concern. The 99% of them are computer illiterate, and I'm only concerned about those among them who may already have a print-to-PDF driver, and would add two and two and start using it as a vehicle to export stuff from the app.

>Even standard network redirection could be tough to handle:
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>1. User sets up a PDF printer on "Server", gives it a share name of "NetPrint"
>2. This printer gets installed on a workstation, as "\\Server\NetPrint". There is no indication in its name that it's a PDF printer driver.
>

>There might be some clue via something like WMI that the remote printer prints to PDF but I wouldn't count on it. Especially if the server computer is Novell, Linux etc.

Don't expect any of that - this app mostly runs on laptops, and I don't expect the average user to be able to get their way through a mixed network, and then to know where did they file actually get created :).

I only need to make it not too easy for this average user to export the content.

>It's worth pointing out that there are a lot of people with legitimate PostScript printers who will be annoyed if you prevent them creating paper output on them.

Yes, I was thinking of this - and those who would know how to use the .ps or .eps files are free to go.

>Finally, there's little preventing a user from optically scanning paper output into files.

Good luck - it's the sheer amount of text that would make this less worthwhile than actually buying the app. I'm trying to make it just sufficiently hard to copy out, so they'd find it easier to simply purchase. The hackers will find a hundred ways to steal this, and my customer doesn't care about hackers. It's the simple user who is happy to use the clipboard to just export the content that he's worried about. Couple of simple deterrents would be enough.

I'll have another thread on another aspect of this - don't want to overload this one.