Re: Unicode String Parameters in DLL's

You've probably heard something wrong about "VBA's automatic converting to
ANSI". Strings in VB6 and VBA are Unicode. (The forms package in VB6 it NOT
Unicode, so you might have heard some stuff about that. VBA's forms package
is Unicode.) I do this exact same kind of thing when calling Windows Unicode
APIs. VB/VBA will see the Unicode characters put in your "buffer" by your
DLL just fine. It doesn't so any kind of conversion before or after the DLL
call.

One thing to watch out for is if your DLL routine puts a zero byte at the
end of the string. To VBA, a zero byte is just another character in the
string (Chr$(0)); it does not terminate the string. You'll need a routine to
scan where the zero byte is and then only take the text before that zero
byte. I can give you a function for that if you need.

--
Tom Winter
tom@xxxxxxxxxxxxxxxxxxxxxx

"Unknown" <unknown@xxxxxxxxxxx> wrote in message
news:_%B2e.8089$zl.7227@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> We are converting our application to work with Unicode. The Word macro in
> our application "communicates" with our main application via a C DLL.
> This DLL includes several functions which return Unicode strings back to
> the macro as input parameters. My question is, what is the correct
> declaration for the DLL functions in VBA?
>
> I currently have it working like this:
>
> Private Declare Function GetUserName Lib "MyDLL.dll" (ByVal lpUser As
> Long) As Integer
>
> GetUserName simply copies the user name into a Unicode string.
>
> I call this function from VBA code with something like this:
>
> Dim sUser as String
> sUser = String(255, Asc(" "))
>
> GetUserName StrPtr(sUser)
>
> This seems to work, but I've only tested it with standard characters (i.e.
> nothing outside of the normal Latin character set). I'm concerned about
> VBA's automatic converting to ANSI, although I don't really understand
> what that means... Does it mean that VBA will convert the sUser string to
> ANSI when I try to access it, and so any characters outside of the ANSI
> set will be converted to question marks or something like that?
>
> Any help you can give me on this would be greatly appreciated.
>


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