Strings DLLs and Excel spreadsheets

[David Pratten]

Does anyone have experience passing strings to and
returning strings from Excel Spreadsheets?

After creating VB Declare Function statements,
the DLL functions are available to the spreadsheet, but
Excel passes and receives 'Rubbish' from the function.

In contrast, the function works fine from the Immediate window
of VBA inside Excel.

There seems to be a difference between the VBA to DLL
'connection' and the Spreadsheet to DLL 'connection'.

Ideas?

Thanks

David

EXAMPLE:

In VBA Module:
Declare Function sdMJDx Lib "sdsun.dll" Alias "sdMJDx" (ByVal Yearx As Long, ByVal Month As Long, ByVal Day As Double, ByVal Hour As Double, ByVal Minute As Double, ByVal Sec As Double, ByVal TimeZone As Double) As String
IN PB DLL
Function sdMJDx Alias "sdMJDx" (ByVal Year As Long, ByVal Month As Long, ByVal Day As Double, ByVal Hour As Double, ByVal Minute As Double, ByVal Sec As Double, ByVal TimeZone As Double) Export As String

Works fine in VBA but return's rubbish from a worksheet.

[E Dingsor]

David,
First hav eyou declared your function as Public ?
If you want to stick with your orginal DLL you may try to wrap the DLL declared function within a userdefined function within a VBA module.
Ex. Public Function NewFunc(Byval ..., byval ) as string
Dim Retstring as string
Retstring = sdMJDx(..,....,....)
NewFunc= Retstring

end function

If you want make a function(PB DLL) that trule speaks with Excel take a look at my usersubmitted(in Powerbasic Archives) excel32api.zip
file


Regards Eigil


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[David Pratten]

Yes on both counts. A related question. Do I aslo need to do the
copy of function parameters that are strings? eg.

Public Function NewFunc(Byval name as string, ..., byval ) as string
Dim Retstring as string
Dim parmstring as string
parmstring = name
Retstring = sdMJDx(parmstring,....,....)
NewFunc= Retstring

end function

or will this do?

Public Function NewFunc(Byval name as string, ..., byval ) as string
Dim Retstring as string
Retstring = sdMJDx(name,....,....)
NewFunc= Retstring

end function

Originally posted by E Dingsor:
David,
First hav eyou declared your function as Public ?
If you want to stick with your orginal DLL you may try to wrap the DLL declared function within a userdefined function within a VBA module.
Ex. Public Function NewFunc(Byval ..., byval ) as string
Dim Retstring as string
Retstring = sdMJDx(..,....,....)
NewFunc= Retstring

end function

If you want make a function(PB DLL) that trule speaks with Excel take a look at my usersubmitted(in Powerbasic Archives) excel32api.zip
file


Regards Eigil

------------------

[E Dingsor]

David,
I don't think you have to "copy" the strings to other string variables within the function in the VBA module. It's been a long while since I used PB DLLs and VBA modules to create userdefined functions. Now I only make function with the OPER and XLOPER parameter types.
I have scanned some old files and I think you have to do the following:
Declare string parameters in your DLL as ASCIIZ ex. Function newFunc(zNewString AS ASCIIZ,......)
In your declare section in the VBA module declare the asciiz strings as BYVAL String.

I think that will do the trick.

Regards

Eigil

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