Hi,
Can someone explain what does this error means?
Webcam error LNK2001: unresolved external symbol "protected: long __thiscall CCaptureVideo::OnGraphNotify(unsigned int,long)" (?OnGraphNotify@CCaptureVideo@@IAEJIJ@Z)
Thanks a lot in advance!
Hi,
Can someone explain what does this error means?
Webcam error LNK2001: unresolved external symbol "protected: long __thiscall CCaptureVideo::OnGraphNotify(unsigned int,long)" (?OnGraphNotify@CCaptureVideo@@IAEJIJ@Z)
Thanks a lot in advance!
It usually means you haven't linked to whatever library or object that contains the function mentioned in the error. It may alternatively be that you've not provided a definition for the function in question. Read your compiler documentation on how to properly link the required library; checking out the error code should also provide useful information, too.
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Caution: this person may be a carrier of the misinformation virus.
Is CCaptureVideo your code or library code?
a code i am learning. It is not a library.
**added**
i should elaborate more.
so i have a header file:
Then in my .cpp file:Code:#define WM_GRAPHNOTIFY WM_USER+1 class CCaptureVideo : public CWnd { protected: afx_msg HRESULT OnGraphNotify(WPARAM wp, LPARAM lp); DECLARE_MESSAGE_MAP() };
i have the constructer, the destroyer then have:
so when i compile, the error mentioned in my first post occurs. if i comment the ON_MESSAGE line.. the compilation runs fine. This should help you guys explain to me more..Code:BEGIN_MESSAGE_MAP(CCaptureVideo, CWnd) ON_MESSAGE(WM_GRAPHNOTIFY, OnGraphNotify) END_MESSAGE_MAP()
Last edited by ang_ks; 07-18-2007 at 08:32 PM.
You should provide a body for the function OnGraphNotify
that will be called on when the message WM_GRAPHNOTIFY occurs
All problems in computer science can be solved by another level of indirection,
except for the problem of too many layers of indirection.
– David J. Wheeler
ahh yes you are right. i did not have my function implementation codes. I just saw an example the moment you posted.
Thanks a lot anyway.
Cheers to all that replied.