VS2005 MFC dialog box global function access member variable __ function

A few days ago to do a program, to achieve real-time video display, and real-time capture, using multithreading. and multithreaded function in order to access the dialog box member variables, compile without errors, but run terminated, prompt

Debug Assertion failed!

File:f:\rtm\vctools\vc7libs\ship\atlmfc\src\mfc\winocc.cpp

To discover the problem of calling class members in thread functions

Refer to this article click Open link

The solution is to declare a global variable void *pdlg first;

dialog box to add Pdlg=this to the initial function;

Functional functions for threads

void Thread1videofunc ()
{
while (1)
{
Cmfc_videodlg *maindlg;
maindlg= (cmfc_videodlg*) Pdlg;
Maindlg->m_showvideo=cvqueryframe (Capture);
MAINDLG->DRAWPICTOHDC (Maindlg->m_showvideo,idc_picture_video);
Sleep (100);
}
}