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How to pass a null pointer trough a "Call Library Function Node" ?

Hello.

I'm developing DLL's and using them in LabVIEW trough the "Call Library Function Node" VI.
I wonder if isn't possible to pass parameters to a function like this:

void getArray(double **array);

Where I just want to pass a NULL pointer in the input, and just in the output I get the array that was builded in the DLL code.

Example of a call to the funtion in C++: 
                                                                   double *array = NULL; //declaration of the array
                                                                  
                                                                   getArray(&array); //call to the function

I've looked to the examples in the LabVIEW directory (ARRAY1DHandle.vi, ARRAY2DHandle.vi, ARRAY3DHandle.vi),
as well as the source code, but in everyone of them I already know what is the size of the outpu array, but I've situations that I don't know that,
because that is done in the DLL.

I appreciate anything that could help me solve this "limitation", or mine or LabVIEW's.

Thanks.
Nelson Neves


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Hello Nelson,

I tried to find your email address but was not successful.

I am developing a PocketPC application and need to develop a simple DLL that can be called from my code.

Please contact me regarding this opportunity

Regards,

Guy R. Hughes

Controlink Systems, LLC

link@eos.net

 

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Hello Guy

When you are creating a DLL for LabVIEW PDA Module use, you need to create two DLL's:
   - one builded for PDA (ARM), you can use EVC to do that;
   - other builded for PC (x86), you can use Visual C++ to do that. NOTE: I've tried Borlad software to do this one and it doesn't works. I believe that you need to use a Microsoft made software to do this.

I leave you this link to one thread that should have all the information tha you need to do this.

LabVIEW PDA reports COREDLL.DLL error when using Call Library Function Node

I hope this help you.


Nelson Neves
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I hope this can help.
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Hello Nelson,

In all fairness to the forum, please contact me privately at link@eos.net.  (I do not have your email address).

I am interested in contracting your services if you believe you can help me.

Regards,

Guy Hughes

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