virtual function problem

[adina]

Hi,
I have 2 classes in my application: class A and class B.
in CaptureDoc.h

class CCaptureDoc : public CWinpcap
{
public:
    CCaptureDoc(wxFrame* capframe, CCaptureWindow* capwindow);
 
     void PacketHandler(struct pcap_pkthdr* pkt_header, const unsigned char* pkt_data);
 
    void WinpcapThreadEnded();
 
    bool m_capmaxperform;
private:
    CCaptureWindow* m_capwindow;
    wxFrame* m_capframe;
};
 

in CaptureDoc.cpp

#include "CaptureDoc.h"
 
CCaptureDoc::CCaptureDoc(wxFrame* capframe, CCaptureWindow* capwindow)
{
   /* here some code */
}
 
void CCaptureDoc::PacketHandler(struct pcap_pkthdr* packet_header, const unsigned char* packet_data)
{
/* here some code */
}
 
void CCaptureDoc::WinpcapThreadEnded()
{
    /* here some code */
}
 

in winpcap.h

class CWinpcap : public wxThread, wxEvtHandler {
/* ... code*/
virtual void PacketHandler(struct pcap_pkthdr* pkt_header, const unsigned char* pkt_data);
virtual void WinpcapThreadEnded(); 
/* code */
}
 

In winpcap.cpp member functions of the CWinpcap class are supposed to call the functions WinpcapThreadEnded() and PacketHandler()

I need the overriden functions in the derived class to get called by the base class and do their job. Is this the right way to solve this problem. However, I get an error LNK2001: unresolved external symbol....

If it cannot be done in this way, what would another way be ?
Any help would be very appreciated :)

Thanks,
Adina

[adina]

An observation to the above post: I don't want the base class to know who is inheriting from it. Therefore I don't instantiate a derived class object or something like it. I suppose that you may see the functions overriden in the derived class as callback functions. Is this possible to be done ?

Thanks,

Adina

[adina]

Hello again,
I've been reading a little about the template method design pattern.
I have put the two virtual functions WinpcapThreadEnded() and PacketHandler() in the base class as protected.
The functions from the base class that call these two functions are public and non-virtual.

Stiil I receive the same linking errors: error LNK2001 unresolved external WinpcapThreadEnded() and unresolved external PacketHandler().

Any ideas to this problem are very much welcomed.

Thanks,
Adina