Passing a VBA array to a C++ dll - Example Needed

[CFDFEAGURU]

Hi all,

In the book "Financial Applications Using Excel add-in Development in C/C++" 2nd edition by Steve Dalton in Section 3.7.2 Passing arrays and ranges from Excel to VBA to C/C++ and in that section a description of how this can be done is given. No example of how to do this is given and he refers to an "example.dll" that isn't provided. This book is horrible written but seems to have all the information buried in it some where.

Could anyone provide a simple example of how to pass a 1-D array or vector from VBA to C++ then do a simple operation on the passed array values and then return the array values to VBA?

Thanks.

 

[chiro]

Hey CFDFEAGURU.

Have you seen this?

http://support.microsoft.com/kb/207931

 

[CFDFEAGURU]

chiro, no I didn't come across that one. Thank. I will see if I can use that.

 

[CFDFEAGURU]

Yes, that methods works perfect. Sorry for the very slow response.

 

[LudusRex]

Hello,

Passing an array from VBA to a C++ dll is a common task in programming financial applications using Excel. Here is a simple example of how this can be done:

1. Create a new C++ dll project in Visual Studio.
2. In the project, create a function that takes in an array as a parameter and returns an array as the result. For example:

double* calculate(double* inputArray, int size)
{
// perform calculations on inputArray
double* result = new double[size];
// store the results in the result array
return result;
}

3. In the VBA editor, declare the function as an external function using the "Declare" statement. For example:

Declare Function calculate Lib "example.dll" (ByRef inputArray As Double, ByVal size As Integer) As Double

4. In your VBA code, create an array and pass it to the C++ function as a parameter. For example:

Dim inputArray(10) As Double
' fill the array with values
Dim resultArray As Double
resultArray = calculate(inputArray, 10)

5. The resultArray variable will now contain the array returned from the C++ function. You can then use this array in your VBA code as needed.

I hope this example helps you understand the process of passing an array from VBA to a C++ dll. Please note that this is a simplified example and may need to be adapted to fit your specific project. It is also important to properly manage memory when working with arrays in C++ to avoid memory leaks. I recommend further research and experimentation to fully understand the concept. Good luck with your project!