Constructs an object of class CDumpContext.
CFile* pFile = NULL
A pointer to the CFile object that is the dump destination.
The afxDump object is constructed automatically.
Do not write to the underlying CFile while the dump context is active; otherwise, you will interfere with the dump. Under the Windows environment, the output is routed to the debugger via the Windows function OutputDebugString.
if (!f.Open(_T("dump.txt"), CFile::modeCreate | CFile::modeWrite))
AFXDUMP(_T("Unable to open file\n"));