Re: DLL function loading issue

From:

"Abdo Haji-Ali" <ahali@inframez.org_use_com_instead>

Newsgroups:

microsoft.public.vc.language

Date:

Sat, 30 Sep 2006 20:38:04 +0200

Message-ID:

<#CQHmaL5GHA.3840@TK2MSFTNGP06.phx.gbl>

"--== Alain ==--" <nospam@noemail.com> wrote in message
news:#u3hXPL5GHA.4064@TK2MSFTNGP03.phx.gbl...

Hi,

I have an issue with loading a function from my DLL.

here is the DLL *.cpp file :
extern "C" __declspec(dllexport) LPTSTR GetString(int Index)
{
   LPTSTR res="";
   LoadString(GetModuleHandle(NULL),Index, res, sizeof(res));
   return(_T(res));
}

here is my class which should load the DLL and open the function :
*.cpp file :
HINSTANCE CARDLLWrapper::InitializeLoc(CString DLLName)
{
  m_hlibLoc=LoadLibrary(DLLName);
  if (m_hlibLoc != NULL)
  {
   LocGetString = (LPTSTR)GetProcAddress(m_hlibLoc, TEXT("GetString"));

Why are you typecasting the return value of GetProcAddress to LPTSTR? And
why are you assigning a value to a type (LocGetString) in the first place!!
LocGetString is a function pointer "type" (notice the typedef). You can
create instances from this type (just like any other type) and asssign value
to these instances... In other words:

LocGetString funcGetString; // Notice that LocGetString was used as a
declarator
funcGetString = (LocGetString)GetProcAddress(m_hlibLoc, TEXT("GetString"));
// Assignment is done to "instances" and "type"-casted

I suggest you look further into typedef.

--
Abdo Haji-Ali
Programmer
In|Framez