将双数组从Visual Basic传递到C ++ DLL

Question

I am trying to pass two double arrays from a handler that's written in VBA into the DLL written in C++ and I keep getting an error saying the index it outside the bounds of the array. The arrays contain 800 double values which I need to calculate the correlation between the two arrays using the FFT

function call in the VBA code:

Dim firstDataDbl() As Double = Array.ConvertAll(firstData, Function(d) Double.Parse(d))
Dim secondDataDbl() As Double = Array.ConvertAll(secondData, Function(d) Double.Parse(d))
rdftTest(UBound(firstDataDbl) + 1, firstDataDbl(0), secondDataDbl(0))

definition of the DLL function in VB:

Public Module DLLTest
   <DllImport("FFT.dll", CharSet:=CharSet.Ansi, CallingConvention:=CallingConvention.Cdecl)>
   Function rdftTest(ByVal length As Integer, ByRef firstDataDblFirstElement As Double, ByRef secondDataDblFirstElement As Double) As Integer
   End Function
End Module

Function, written inside the C++ DLL:

void rdftTest(int length, double *input1, double *input2) {
   std::ofstream myFile;
   myFile.open("C:\\randFolder\\foo.txt", std::ios::out);
   myFile << length << " " << &input1 << " " << &input2 << std::endl;
}

Both arrays are always of equal length which is why i'm using only one length argument.

Answer 1

我通过将UBound(firstDataDbl) + 1解析为Integer解决了该问题，然后在函数中传递了该值