Access Violation

[APE47]

Hi,

I'm having a spot of bother with GDTwain. Having been using the software, under DELPHI v7, for over a year now (and happy with its performance) I was required to re-install a PC system (windows etc) and now I get an access violation when performing most actions (such as twain1.TwainGetSourceCount, twain1.TwainSelectSource(0)). Also TWAIN_SelectSource creates an empty selection panel, but whether this is prior to the access violation or as a result of it is unclear.

If its any use twain1.TwainIsAvailable returns TRUE

Trying the code on another PC it works fine. I've installed GDTWainPro2.ocx (and registered it), gdiplus.dll, msvbvm60.dll and gdtwain.dll.

I'd almost say that its a windows/twain function that is uninstalled or outdated but I have no idea what. Can you help?

Thanks in advance
Andrew

[Loïc]

Hi Andrew,

Please give me some details:

- What operating system are you using
- Are you using the last version of GdTwain ?
- Could you write me a very simple Delphi application to reproduce the behavior ?


With best regards,

Loïc

[APE47]

Hi,

Operating System:
Windows XP Professional SP3

Twain:
For the last year I have been using GDTwain Pro OCX Toolkit TWAIN ActiveX (#300181558) but after needing to reinstall the PC I found that I no longer had the installation kit. I sent a email to esupport on 03/03/2009 requesting an archive copy (only Pro 2 seems to be available on your download site) but got no reply. I have therefore had to installed GDTwain Pro 2 OCX, but my licence key is invalid so I'm having to work with a temporary one (thats a different issue which I wish to resolve)

Code:
All I need to do to get the error is

twain1.SetLicenseNumber('...valid key...');
twain1.TwainSelectSource(0);

At the TwainSelectSource the selection panel appears, but contains no entries (I know there are 2 devices) and an access violation panel (at address 00004 read of address 00004) appears.

As I previously stated, if I move this code to another PC, and install the redistribution ocx/dlls, it works fine. I think its something on the specific PC within windows (a file missing, not installed or something) but I do not know enough about Twain support to figure it out. I have checked the Twain.dll, Twain_32.dll, Twunk_16.exe and Twunk_32.exe exist.

Thanks in advance
Andrew

[Loïc]

Hi Andrew,

I sent a email to esupport on 03/03/2009 requesting an archive copy (only Pro 2 seems to be available on your download site)

I gave you a reply. Please, use another email. I will send you a free update for GdPicture Pro 2.

Code: Select all

At the TwainSelectSource the selection panel appears, but contains no entries (I know there are 2 devices) and an access violation panel (at address 00004 read of address 00004) appears.

OK, this is a problem between your OS and the TWAIN DSM (Twain_32.dll). You should report this problem on the http://www.twain.org group (the publisher of the TWAIN SDM). I suggest you are using a bad version of the DSM or you copied it within a bad directory.

With best regards,

Loïc

[APE47]

Loic,

Thanks for that. I thought as much, I'll pursue the problem with the TWAIN group.

Regarding the update, I'll send another email from a different address.

Thanks very much for the help
Andrew