Calling LabVIEW DLL in Visual C++ That Passes Array Handles by Reference

[ExamplePrograms]

Overview

This example demonstrates the syntax necessary for passing array handles between an external coding environment and a shared library (DLL) you create in LabVIEW. Array_Multiply.vi has an input array and an output array. The VI generates the output array by multiplying each element of the input array by two. A build script, Build Array_Multiply.bld, builds the VI into a shared library that passes these parameters as array handle pointers. Array_Multiply.lib and Array_Multiply.h are the library and header files that the build creates.

The Call Array_Multiply DLL folder contains the files for the workspace of the same name, as well as the Array_Multiply.dll. The main code of the project allocates memory for the handle pointers and initializes the arrays to which they point.

Note: To make the example as simple as possible, each array contains only one element.

Print statements write the value of the first element of the output array to a console before and after a call to the shared library. You will see that the call to the shared library changes the value of the output array.

Note: You might need to reattach labview.lib to the project. You can find this file in the labview\cintools directory.