🚀 go-pugleaf

Roger Warren wrote:

> Thank you all for your input. I have much to consider, and will look
> at 'Packages' before making any rash decisions.

The alternative way to 'export' objects from a DLL is to use a handle
based methodology. The handle can either be an index into an array of
object pointers (held DLL side) or a pointer to the object instance
itself. For the latter option it is usually prudent to present the
pointer to the outside world as a 'void *' so as to deter the caller
from attempting to dereference it directly.

Basically this means that your method:

void TestDLLClass::TestMethod(AnsiString &s)
{
  Application->MessageBox(s.c_str(), "DLL", MB_OK);
}

Would become either:

void TestDLLClass::TestMethod(AnsiString &s,
                              int         handle)
{
  myObjects[ handle ]->MessageBox(s.c_str(), "DLL", MB_OK);
}

or

void TestDLLClass::TestMethod(AnsiString &s,
                              void * handle)
{
  reinterpret_cast<TMyObject *>( handle )->
    MessageBox(s.c_str(), "DLL", MB_OK);
}

Both methods have good and bad points but there's not a lot to choose
between them. If you do go that route post for further advice since the
above examples are a bit crude and could be 'prettified' :)

But if you decide you do want to export classes as you originally
proposed then there's nothing wrong with that. My comments were just
pointing out a possible issue.
-- 
Andrue Cope [TeamB]
[Bicester, Uk]
http://info.borland.com/newsgroups/guide.html