[Python.NET] Problem to use a dll: System.ApplicationException: Error 1: OpenDevice: Invalid handle

Bradley Friedman brad at fie.us
Wed Jan 16 22:21:09 CET 2013


The invalid handle suggests you're already inside windows land when it excepts. Your python and .net are both 64 bit. What about the dll you are importing?  There are ways to make .net incompatible between bitnesses.  When you run in iron python, is it running 32 bit or 64 bit? Best verify bitness across your control fully, just to rule it out. 

Sent from my iPad

On Jan 16, 2013, at 3:49 PM, Daniel Krause <krausda at gmx.de> wrote:

> Hi Brett,
> 
> to check your suggestion I added a print statement to the script (after clr.AddReference("xiAPI40.NET"):
> 
> print sys.path
> 
> The result looks ok to me:
> 
> ['C:\\Users\\mdk\\workspace\\camera\\', 'C:\\Python27\\lib\\site-packages\\distribute-
> 0.6.21-py2.7.egg', 'C:\\Python27\\DLLs', 'C:\\Python27\\lib', 'C:\\Python27\\lib
> \\plat-win', 'C:\\Python27\\lib\\lib-tk', 'C:\\Python27', 'C:\\Python27\\lib\\si
> te-packages', 'C:\\Python27\\lib\\site-packages\\setuptools-0.6c11-py2.7.egg-inf
> o', 'C:\\Users\\mdk\\.eclipse\\org.eclipse.platform_4.2.0_248562372\\plugins\\or
> g.python.pydev_2.7.1.2012100913\\pysrc\\pydev_sitecustomize', 'C:\\Windows\\syst
> em32\\python27.zip', 'C:\\Python27\\lib\\site-packages\\PIL', 'C:\\Python27\\lib
> \\plat-win', 'C:\\Python27\\lib\\site-packages\\setuptools-0.6c11-py2.7.egg-info
> ', 'C:\\Python27\\lib\\site-packages\\setuptools-0.6c11-py2.7.egg-info', 'C:\\Wi
> ndows\\Microsoft.NET\\Framework64\\v4.0.30319\\']
> 
> I also copied the folder to a temp folder and run the script from there without adding the new path explicitly to the python path.
> 
> The new location is then automatically added to the path, and the console output looks the similar.
> 
> C:\temp\camera> python.exe .\testcam.py
> ['C:\\temp\\camera', 'C:\\Python27\\lib\\site-packages\\distribute-0.6.21-py2.7.egg', 'C:\\Windows\\system32\\python27.z
> ip', 'C:\\Python27\\DLLs', 'C:\\Python27\\lib', 'C:\\Python27\\lib\\plat-win', 'C:\\Python27\\lib\\lib-tk', 'C:\\Python2
> 7', 'C:\\Python27\\lib\\site-packages', 'C:\\Python27\\lib\\site-packages\\PIL', 'C:\\Python27\\lib\\site-packages\\setu
> ptools-0.6c11-py2.7.egg-info', 'C:\\Windows\\Microsoft.NET\\Framework64\\v4.0.30319\\', 'C:\\Users\\mdk\\workspace\\camera\\']
> Traceback (most recent call last):
>   File ".\testcam.py", line 9, in <module>
>     cam.OpenDevice(0)
> System.ApplicationException: Error 1: OpenDevice: Invalid handle
>    at xiApi.NET.xiCam.throwException(Int32 errNum, String param)
>    at xiApi.NET.xiCam.OpenDevice(Int32 DevID)
> 
> Best regards
> Daniel
> 
> 2013/1/15 Tribble, Brett <btribble at ea.com>
>> You might try making and swapping in a simple assembly that opens a command prompt so that you can inspect the environment variables. For me, this is almost always a system path / current directory issue. Hopefully I’m not leading you down a false road.
>> 
>>  
>> 
>> From: m.daniel.krause at googlemail.com [mailto:m.daniel.krause at googlemail.com] On Behalf Of Daniel Krause
>> Sent: Tuesday, January 15, 2013 1:44 PM
>> To: Tribble, Brett
>> Subject: Re: [Python.NET] Problem to use a dll: System.ApplicationException: Error 1: OpenDevice: Invalid handle
>> 
>>  
>> 
>> No, I don't have the source, only the dll.
>> 
>>  
>> 
>> But thanks for the sugggestion.
>> 
>> Daniel
>> 
>>  
>> 
>> 2013/1/15 Tribble, Brett <btribble at ea.com>
>> 
>> I assume you don’t have the source to the .dll?
>> 
>>  
>> 
>> If you do, you can add a line to use debug the error using System.Diagnostics.Debugger.Break():
>> 
>>  
>> 
>> http://msdn.microsoft.com/en-us/library/system.diagnostics.debugger.break.aspx
>> 
>>  
>> 
>>  
>> 
>>  
>> 
>> From: PythonDotNet [mailto:pythondotnet-bounces+btribble=ea.com at python.org] On Behalf Of Daniel Krause
>> Sent: Tuesday, January 15, 2013 12:42 PM
>> To: pythondotnet at python.org
>> Subject: [Python.NET] Problem to use a dll: System.ApplicationException: Error 1: OpenDevice: Invalid handle
>> 
>>  
>> 
>> I am trying to use a dll to control a camera.
>> 
>> It is possible for me to use the dll with ironpython, but I fail to use it with python for .NET (CLR 4.0).
>> 
>> (And I would like to use e.g. numpy as well, so I need python for .NET).
>> 
>>  
>> 
>> Below follow a short test script, the python / ironpython versions and their console output when running the test script.
>> 
>>  
>> 
>> Any hints are welcome.
>> 
>> Thank you
>> 
>> Daniel
>> 
>>  
>> 
>> ########################################################
>> 
>> #test script "testcam.py" #1 for python for .NET
>> 
>> import clr
>> 
>> import sys
>> 
>> sys.path.append("C:\\Users\\mdk\\workspace\\camera\\")
>> 
>> clr.AddReference("xiAPI40.NET")
>> 
>> from xiApi.NET import *
>> 
>> cam = xiCam()
>> 
>> cam.OpenDevice(0)
>> 
>> print cam.GetParamString(PRM.DEVICE_NAME) #print device name
>> 
>>  
>> 
>> ###############
>> 
>> #console output showing the python version, 
>> 
>> #installed is .NET-support with pythonnet-2.0dev.clr4.0.win-amd64-py2.7.exe on Win7 64bit
>> 
>> PS C:\Users\mdk\workspace\camera> python.exe
>> 
>> Python 2.7.3 (default, Apr 10 2012, 23:24:47) [MSC v.1500 64 bit (AMD64)] on win32
>> 
>> Type "help", "copyright", "credits" or "license" for more information.
>> 
>>  
>> 
>>  
>> 
>> ###############
>> 
>> #running test script #1 with python, console output
>> 
>> Traceback (most recent call last):
>> 
>>   File "C:\Users\mdk\workspace\camera\testcam.py", line 8, in <module>
>> 
>>     cam.OpenDevice(0)
>> 
>> System.ApplicationException: Error 1: OpenDevice: Invalid handle
>> 
>>    at xiApi.NET.xiCam.throwException(Int32 errNum, String param)
>> 
>>  
>> 
>>    at xiApi.NET.xiCam.OpenDevice(Int32 DevID)
>> 
>>  
>> 
>> ######################################################
>> 
>> #test script "testcam.py" #1 modified for ironpython, test script #2
>> 
>> import clr
>> 
>> import sys
>> 
>> sys.path.append("C:\\Users\\mdk\\camera\\")
>> 
>> clr.AddReference("xiAPI40.NET.dll")
>> 
>> from xiApi.NET import *
>> 
>> cam = xiCam()
>> 
>> cam.OpenDevice(0) 
>> 
>> print cam.GetParamString(PRM.DEVICE_NAME)   #print device name
>> 
>>  
>> 
>> ###############
>> 
>> #console output showing the ironpython version
>> 
>> PS C:\Users\mdk\workspace\camera> ipy.exe
>> 
>> IronPython 2.7 (2.7.0.40) on .NET 4.0.30319.17929
>> 
>> Type "help", "copyright", "credits" or "license" for more information.
>> 
>> >>> 
>> 
>>  
>> 
>> ##############
>> 
>> #running test script #2 with ironpython, console output
>> 
>> MQ013MG-E2
>> 
> 
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