sujet Re: Help with passing VBA string to Fortran dans Intel® Fortran Compiler

Help with passing VBA string to Fortran

ripittard — Wed, 06 Apr 2022 23:10:33 GMT

I am trying to pass a VBA string to fortran, modify it and return the result and am having some trouble.

I thought I could have VBA pass the size of the string and a reference to the string to Fortran and then use ConvertBSTRToString to obtain the Fortran equivalent, but I am struggling to do this correctly.

The lenght of the string comes across OK, but ConvertBSTRToString result does not match and the string content in Fortran does not match. Any help woudl be appreciated.

The Fortran routine and VBA code are attached.

Thanks,

Re: Help with passing VBA string to Fortran

FortranFan — Thu, 07 Apr 2022 03:02:27 GMT

@ripittard ,

This post may be of limited value to you since what is below is prescriptive. But if interested, take a look at this thread which has Fortran with VB.NET (a different beast of course) : https://community.intel.com/t5/Intel-Fortran-Compiler/x64-string-passing/td-p/1373313

But you can consume the same Fortran subroutine shown in it in Microsoft Office VBA as follows: the key aspects are ByVal attribute for the string parameter and (preferably) LongPtr type to match with preferably c_size_t kind for the integer on the Fortran side, this one too as ByVal:

Option Explicit Public Declare PtrSafe Sub Fstr Lib "c:\temp\Fdll.dll" (ByVal Str As String, ByVal LenStr As LongPtr)

And a trivial button example below to see how the subroutine can be invoked in Excel:

Private Sub cmdBtn_Click() Dim LenStr As LongPtr Dim Str As String On Error GoTo StrErr Range("Str").Clear LenStr = Range("LenStr").Value If (LenStr > 0) Then Str = String(CLng(LenStr), " ") Call Fstr(Str, LenStr) Range("Str").Value = Str Else Range("Str").Value = xlErrNA End If Exit Sub StrErr: Range("Str").Value = xlErrNA End Sub

Re: Help with passing VBA string to Fortran

ripittard — Thu, 07 Apr 2022 21:50:14 GMT

Thanks FortranFan, that gave me exactly what I was after!