Re: ctypes and twain_32.dll

2011-05-03 Thread Patrick Vrijlandt
On 2 mei, 20:56, Michel Claveau -
MVPenleverlesx_xx...@xmclavxeaux.com.invalid wrote:
 Hi!

 On my system, thera are not twain32.dll or twain_32.dll, but twain.dll

 @+
 --
 Michel Claveau

Hi,

I have both. They are correctly installed and working. ctypes gives a
different response if it cannot find the requested DLL.

Patrick
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Re: ctypes and twain_32.dll

2011-05-02 Thread Michel Claveau - MVP
Hi!

On my system, thera are not twain32.dll or twain_32.dll, but twain.dll

@+
--
Michel Claveau 

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ctypes and twain_32.dll

2011-04-30 Thread Patrick Vrijlandt
Hi,

I'm trying to access TWAIN from python 3.2 on Vista, using ctypes. I'm
stuck at line 2:

PythonWin 3.2 (r32:88445, Feb 20 2011, 21:29:02) [MSC v.1500 32 bit
(Intel)] on win32.
 from ctypes import *
 windll.twain_32
Traceback (most recent call last):
  File interactive input, line 1, in module
  File C:\Python32\lib\ctypes\__init__.py, line 410, in __getattr__
dll = self._dlltype(name)
  File C:\Python32\lib\ctypes\__init__.py, line 340, in __init__
self._handle = _dlopen(self._name, mode)
WindowsError: [Error 1114] Een initialisatieroutine van de dynamic
link library (DLL-bestand) is mislukt

[Yes, I'm Dutch. It says: An initialisation procedure of the DLL has
failed]

This is from a .NET / TWAIN example on http://www.codeproject.com:

As the TWAIN API is exposed by the Windows DLL, twain_32.dll, we have
to use the .NET DllImport mechanism for interop with legacy code. This
DLL has the central DSM_Entry(), ordinal #1 function exported as the
entry point to TWAIN. This call has numerous parameters, and the last
one is of variable type! It was found to be best if we declare
multiple variants of the call like:

[DllImport(twain_32.dll, EntryPoint=#1)]
private static extern TwRC DSMparent(
[In, Out] TwIdentity origin,
IntPtr zeroptr,
TwDG dg, TwDAT dat, TwMSG msg,
ref IntPtr refptr );

I suspect that initialisation may fail because of missing arguments,
but I see no way of sending any arguments. Also, contrary to the .NET
example,  I cannot express that the DLL entrypoint has ordinal 1. Of
course, I may be totally wrong!

I'm hoping for your suggestions!

TIA,

Patrick
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