A question about marshaling (String to CString)

[mirek]

Hi,
I'm trying to import my old code to the .NET using managed wrappers.
I've read "Managed Extensions for C++ Migration Guide" document and was
trying to do what it stated in it. For example if my function takes
mfc's CString I was converting it this way:
char __pin* szUser =
static_cast<char*>(Marshal::StringToHGlobalAnsi(sUser).ToPointer());

and pass szUser to the function.

Today I've found that I can easily pass *String to the function that
takes CString and it works! I'm now little confused, could someone
explain it? When I have to marshal arguments, when i don't? I thought I
have to marshal all arguments.

The second question: what about marshaling and return values? I mean
marshaling value from the return statement in unmanaged function.

Regards,
mirek

 

[Mirek Rewak]

Sorry, it seems that this doesn't work reliable. Sometimes it works
(proper string is passed to the function) sometimes doesn't
But I though it won't even compile.

Regards,
mirek

 

[Nishant S]

CString has a constructor that takes a String and therefore String to
CString conversions are done automatically for you. And String has
constructors that respectively take a __wchar_t* and a char*; and since
CString has an implicit cast to LPCTSTR, CString to String conversions are
almost always done automatically too.