Deserialization stops working if I load MFC DLL from regular DLL

Question

Deserialization stops working if I load MFC DLL from regular DLL.

I have been asking this question before, but at that time I think it was to complex so I did not get any answer solving the problem for me. See C# .NET User Control inside native app. Resource chain problems

Now I have made a test application showing the same problem. You can find the zipped code files at https://skydrive.live.com/?#cid=0977B1167FE01BB3&id=977B1167FE01BB3%21105&sc=documents.

If I load a MFC extension DLL from a regular DLL then deserialization stop working if I call the MFC Extension DLL directly from the application.

enter image description here

When I try to deserialize I get the following CArchiveException "an unnamed file contained an unexpected object."

In addition the output in Visual Studio 2008 gives the following information when I run the debug version of SerializeTest:

“Warning: Cannot load CSerializableClass from archive. Class not defined. CArchive exception: badClass. First-chance exception at 0x7c812afb in SerializeTestD.exe: Microsoft C++ exception: CArchiveException at memory location 0x0012edf8.”

The following test code is run in CMFCDLL::DoIt

void CMFCDLL::DoIt(void)

{

    BYTE * pBuf = (BYTE *)new char [1024];
    {
        CSerializableClass *pSerializableClass = new CSerializableClass;

        CMemFile mf;
        mf.Attach(pBuf, 1024);

        CArchive ar(&mf, CArchive::store);
        ar << pSerializableClass;
        ar.Close();
        mf.Detach();

        delete pSerializableClass;
    }
    {
        CSerializableClass *pSerializableClass = NULL;

        CMemFile mf;
        mf.Attach(pBuf, 1024);
        CArchive ar(&mf, CArchive::load);
        try
        {
            ar >> pSerializableClass;
            ar.Close();
            mf.Detach();

            ASSERT(pSerializableClass && pSerializableClass->GetText() == _T("This is a serialize test"));

            delete pSerializableClass;
        }
        catch(CArchiveException *p)
        {
            char str[500];
            p->GetErrorMessage(str,500);
            AfxMessageBox(str);
            p->Delete();

            ar.Abort();
            mf.Detach();
        }
    }
    delete pBuf;

}

The code that fails is "ar >> pSerializableClass". Any ideas why I get this problem?

Why do I have to use a regular DLL?
I am writing a .NET wrapper and the mixed mode DLL is a regular DLL accessing serialization in a MFC Extension DLL.

score 1 · Answer 1 · answered Jan 25 '12 at 11:50

The question has been answered on MSDN. See http://social.msdn.microsoft.com/Forums/en-US/vcgeneral/thread/d44e910c-a72e-43c0-b67f-8bb08b84aee6/?prof=required.

The MFC DLL was removed from the applications resource chain and added to the regular DLL resource chain. It must exist in both.

Deserialization stops working if I load MFC DLL from regular DLL

1 Answers1