Environment: VC6, SP4, 2K, SP2
This article explains a better way of calling a function in an EXE file from a dependent DLL of the same EXE. In other words, calling a DLL’s function from an EXE is the normal way; this is the reverse of the same.
On CodeGuru I have found a couple of FAQs talking about the same issue. They tell you to have a call back function to hold the pointer from the EXE and so on, but they look primitive. In this article, I have given a better method of calling functions from the EXE. I would be glad if this helps someone in need.
In the EXE:
// Do exactly as you would export a DLL…
extern “C”
{
EXPORT void ExeFn(char * lpszMessage)
{
MessageBox(NULL,lpszMessage,”From Exe”,MB_OK);
}
}
In the DLL:
...
// Get the handle of the EXE that loaded us.
FnPtrT FnPtr = (FnPtrT)::GetProcAddress(GetModuleHandle(NULL),
"ExeFn");
if(FnPtr)
(*FnPtr)("Message From The DLL");
else
MessageBox(NULL,"It Did Not work :(","From DLL",MB_OK);
...
Downloads
Note: In this demo project, I have just implemented the above-mentioned exports. The EXE calls the DLL's function and that function calls a function in the EXE. Those functions do nothing more than display message boxes, so there's no point in giving a demo EXE. Just build the source; you must get the DLL and EXE.
How to Build It
Extract the source zip file. Open workspace "ExportingExe.dsw".
Ensure that ExportingExe is the active project. Now, you can build and run it.
Because Importing.DLL is a dependency of the other one, you don't have to bother about anything else.
Download source - 16 Kb