moshe_n@meuhedet.co.il wrote:
> Hi I get a Dll that call the scaner from some company what shuld I do
> to use this Dll
> to call the scaner from my data base

First of all, I'm pretty sure you can't use MFC from Access, so your
question probably isn't topical here (but as has been mentioned,
traffic here isn't generall so high that this is likely to cause a
major problem).

In any case, it'll depend on what sort of DLL you're dealing with.
There are three reasonably common possibilities for talking to
scanners: WIA, TWAIN and proprietary solutions.

WIA is mildly retarded, so to speak -- if often gives only a relatively
restricted set of options for scanning. It's also implemented as a set
of COM interfaces, so you'll need to talk to it about like you do to
other COM stuff. If you're using WIA, you won't talk directly to the
DLL they've provided at all -- you talk to the WIA objects, and they
use the DLL as appropriate.

Using a TWAIN DLL is a little the same -- you deal with TWAIN, and it
deals with the DLL, the scanner, and so on. TWAIN was designed to allow
much greater flexibility than WIA -- at the expense of being somewhat
more complex to deal with well. In fact, there's an entire cottage
industry built solely around making TWAIN somewhat less of a PITA to
use. Unfortunately, most of these attempts are only partially
successful at best (and some actually seem even more difficult than
TWAIN is itself). I'm conivnced that after TWAIN was developed, there
was a meeting in which to design a special 8th ring of hell exclusively
for its designers...

If the vendor decided to avoid both of the bad choices above, you'll
have something proprietary to deal with. Unfortunately, only the
manufacturer can probably tell you much more about it -- except to warn
you that the few I've seen like that seem to have avoided the
standardized garbage only to invent something that was actually worse.

I know this sounds awfully negative, but in this case, it's more or
less unavoidable -- the standard scanner interfaces really are a
ridiculous mess.

--
Later,
Jerry.

The universe is a figment of its own imagination.