How to - string in DLL

[WojTec]

There is another problem - compatibility Ansii/Unicode.
DLL is compiled with D2010, it uses unit with string type.
In API unit I strings declared as AnsiString:

Delphi-Quellcode:

S: AnsiString;
S := FuncReturnsString();
StrLCopy(lpBuffer, PAnsiChar(AnsiString(S)), nSize) // second typecast is from old version

If both DLL and app are compiled in Ansii compiler (D7) - it working, if in Unicode (D2010) - also working. Of one compiled in Ansii and second in Unicode, then raises invalid pionter operation exception, but buffers has correct data. I don't understand. What I'm doing wrong?

[jaenicke]

I think this is a problem with the size parameter.

You always have to have in mind that one character is one byte in Delphi 7 and two bytes in Delphi 2010.

How does the code for reserving the memory, ... look like?

[WojTec]

Hm, my functions working as in example on 1st page in this thread, size is length of S, in Ansii should be S length, but in Unicode length * 2 if we talking about bytes nor string length, but the same code working if both EXE and DLL are Ansii OR Unicode. So, what I should to do?