Hi there,

I've been trying to create an MFC extension Dll.
What I want to do, is to pass a pointer to an MFC derived object (based on
CDialog)
to my Dll, and from within the Dll, I want to call the memberfunctions of
the CDialog class.

Now, when trying to call the memberfunctions that I've declared, only
results in an "unresolved external".
When calling a 'standard' function, like SetWindowText, it works.

What do I have to do to be able to call 'my own' memberfunctions ??

BTW the code looks like this:

Code in .exe:

class CTestDlg : public CDialog
{
...
void TestFunc(){ AfxMessageBox(_T("Hello"));};
...

Exported function in Dll which is called from .exe
__declspec(dllexport) void DllFunc(CTestDlg* pDlg)
{
    ...
    pDlg->TestFunc();
    ...

Regards

Svend Langen

The exported function in your DLL should read:

    void __declspec(dllexport) DllFunc(CTestDlg* pDlg)

Also, exporting functions from within an EXE is not common.  Your
MFC-extension DLL should be just that, a DLL.

On Thu, 26 Mar 1998 15:35:28 +0100, "Svend Langen"

First put an abstract class in your DLL
        // abstractdialog.h
        class CAbstractDialog : public CDialog
        {
                ...
        public:
                virtual void TestFunc()=0 ;
        } ;

Then derive from it in your exe

        #include "abstractdialog.h"          
        class CTestDlg : public CAbstractDialog
        {
                ...
        public:
                virtual void TestFunc() ;
        } ;

The DLL only knows about the abstract class, not the derived class, so
change the dll function as follows:

        __declspec(dllexport) void DllFunc(CAbstractDialog* pDlg)
        {
            ...
            pDlg->TestFunc();
            ...
        }

You could also put "virtual void TestFunc()=0 ;" in a mixin class and
use multiple inheritance or pass a pointer to the function you want to
call to DllFunc().

Don Grasberger
(remove --- from address to e-mail)