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prodat

2 Posts

Posted - Sep 03 2020 :  07:49:59  Show Profile  Reply
Moin,

on some computers we have the problem that no scanners are found, both WIA and TWAIN.

Scanning via ImageEnVect.IO.Acquire without prior checks or selection of the scanner works.
And the same with ImageEnMView.IO.Acquire never delivers an image there.
In our current program with ImageEn 8.7.6 or 9.1.1, ImageEnVect.IO.Acquire works, but I couldn't find out why, because in a small test program it never works on the affected computers, regardless of whether I select a scanner beforehand or directly use the standard.

When reading out, 0 is always returned on the computers concerned.
MIO/IO.WIAParams.DevicesInfoCount
MIO/IO.WIAParams.DevicesInfo[i].Name
MIO/IO.TWainParams.SourceCount
MIO/IO.TWainParams.SourceName[i]
And MIO/IO.SelectAcquireSource([ieaWIA, ieaTWain]) says there are no scanners.
> No acquisition devices could be located on your computer.

It also doesn't matter whether the component lies on the form or is only used internally in an invisible manner.
At the beginning I still had the hope that it was due to the missing parent, since initially the problem only occurred there and it worked in the window.

attach/prodat/20209374753_IEAcquireTest.zip
2481.09 KB


[edit]
Just tested again with your demos and they worked.
> AllAcquire TwainDemo WIAScanner
Even my test program and our application compiled this morning are now working correctly.
On one of my test computers, where it happened not to work, while I never had a problem on my development computer.

Tomorrow we have to check whether our customer's problem has now been resolved, as I've still fix a few things.
I also found an older problem that occurred when multiple scanners or scanner drivers were present.
Error in the code resulting in the wrong scanner being selected.

But it's still strange that I have been able to understand the problem here since yesterday, which the second major customer is now complaining about, but the problem can only be reliably reproduced on one computer in just one user account, while it works everywhere else.

xequte

6420 Posts

Posted - Oct 07 2021 :  16:48:45  Show Profile  Reply

Also, user-reported solution for similar issue:
 
We found the error on the server 2019 machine. It was a new machine and had a %temp% path containing nordic characters. On the old machine they had changed the nordic character to ascii 'o' in the path. That's why the first call to GETFIRST in twain hanged. ietwainlog.txt was still written so it had to be something with twain but I don't know exactly.


Nigel
Xequte Software
www.imageen.com
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