"This class contains no public constructors" message

[Michael-B]

Hi Diller,

Would it be possible for you to reproduce this behavior in an English version of LabVIEW?  In particular, it would be really helpful to see what the error message says in English.  I think this would help the online community better assist you.

Have a great day!

[Diller]

Hi, Michael,

Thank you for reply.

I have tried in English version of LabVIEW 2011, but there is also a same problem like before.

Because of my Windows OS is Chinese version, so the error message is still in Chinese.

Google translate it as bellow:

LabVIEW 11.0 Development System has encountered a problem need to close. We apologize for the inconvenience.

---------------------------------------------------------------------------------------------

If you are in the process of which the information may be lost.

[Button]Debug                            [Button]Close

[Michael-B]

Hi Diller,

So to clarify, when you run that code in either LV 2010 (Chinese version) or LV 2011 (English Version), LabVIEW crashes and you get a Windows error message saying that "LabVIEW 11.0 Development System has encountered a problem need to close. We apologize for the inconvenience."

Is this correct?

[Diller]

Hi, Michael,

According to your words, the error message really comes from Windows, because the two are in Chinese.

[Garima]

Hi Michael,

I am trying to use CyUSB.dll in LabView and facing the exact same issue.
Can you tell the solution or the cause of the problem?

Thank you,

Garima

[JoelWhittC]

Hello Garima,

The "LabVIEW 11.0 Development System has encountered a problem need to close. We apologize for the inconvenience." error is a very general error. To determine the root cause of the crash I will need to know more about your LabVIEW code.

Are you getting this message every time you execute the code?

Can you post your code or screen shots?

Does your code work without the dll calls?

Are you able to make other calls to diffferent dlls?

Thanks,

Joel C

National Instruments

[Garima]

Hi Joel,

Thank you for your immediate response. Here is some more detail on my project and what I have seen till now.

1. We are trying to use the dll CyUSB.dll which is a .NET library. Used the constructor nodes, invoke methods node etc. As soon as the get_Item method is called, the system crashes. As per what I have noticed it crashed when there is finite reference to pass. If there is no USB device attached, the reference passed is null and LabVIEW does not crash. Also, the get_Item method is not something directly given with the API documentation. I know that its a standard method and should work. But because I could not find any other cause of malfunction I doubt this; so please confirm to me that get_Item method is not a problem.

2. Does the library Systems.Windows.Forms have anything to do with the get_Item? I'm not a software person and thus have lesser information on dll and their use. When I view the .NET Assemblies in Memory, the path for this library is C:/Windows/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a561934e089/System.Windows.Forms.dll although the library is located at the location C:\Windows\assembly\System.Windows.Forms and the internal name for this file is System.Windows.Forms.dll. Screen3.gif.

3. Also, Is it alright to use a dll that communicates with the PC hardware like CyUSB.dll? My questions are very basic, please bare with me.

Here are the answer to your questions:

1. Are you getting this message every time you execute the code?

Ans. As told in point 1. I get this only when I have attched a device and thus the count is non-zero. The VI I have attached can detect a HID device like a mouse. So you can reproduce the issue by connecting a mouse.

2.Can you post your code or screen shots?

Ans. I am posting the code VI, screen shot of the errors received. Screen1 is received first and Screen2 the second. I have also added the document for details on CyUSB.NET for your convenience.

3. Does your code work without the dll calls?
Ans. It has only dll calls.

4. Are you able to make other calls to diffferent dlls?

Ans. I have not tried any other dll.

Thank you again,

Best Regards,

Garima

[Garima]

I have tried several times.. but im unable to attach the project here...
Im trying individual files now.
Please keep them in one folder and then open it. Also, change the extension of CyUSB.pdf to CyUSB.dll.

Thanks,
-Garima

[Garima]

adding the pdf document.

The CyUSB.NET.pdf are the details of the Methods and details of the APIs.

The Screen1, Screen2 and Screen3 are in the next thread. As one thread maximum three attachments.

-Garima

[Garima]

Adding the Screenshots

-Garima

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