C / C++ / MFC

<code>
define WM_WINSOCK 12345

SOCKET theSocket = socket(AF_INET, SOCK_DGRAM,0);

	if(theSocket == SOCKET_ERROR)
	{
		MessageBox("Failed socket()");

	}

		//Fill in the sockaddr_in struct

	bool sock_opt = TRUE;
	setsockopt(theSocket, SOL_SOCKET, SO_REUSEADDR, (char*)&sock_opt, sizeof(sock_opt) );
	// i have to use socket reuse later


	HWND Window; 
	
	HINSTANCE m_hInstance = AfxGetInstanceHandle();

	Window = CreateWindow("Hidden_Winsock_Window",
			"Winsock Window",
			WS_OVERLAPPEDWINDOW,
			CW_USEDEFAULT,
			0,
			CW_USEDEFAULT,
			0,
			NULL,
			NULL,
			m_hInstance,
			NULL);

	// initialize the window class attributes.
	WNDCLASS *windowClass;
	windowClass = new WNDCLASS;
	windowClass->lpszClassName = "Hidden_Winsock_Window";
	windowClass->style = CS_HREDRAW | CS_VREDRAW;

// THE problem is here........
	windowClass->lpfnWndProc = MsgRouter;
///
	windowClass->cbClsExtra = 0;
	windowClass->cbWndExtra = 0;
	windowClass->hInstance = m_hInstance;
	windowClass->hIcon = NULL;
	windowClass->hCursor = NULL;
	windowClass->hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
	windowClass->lpszMenuName = NULL;
	::RegisterClass(windowClass);

	WSAAsyncSelect(theSocket, Window, WM_WINSOCK, FD_READ | FD_WRITE | FD_CONNECT | FD_ACCEPT | FD_CLOSE);
	// binding for reuse. p57 windows socket net prog, actually optional for simple prog//
	bind(theSocket, (LPSOCKADDR)&clientInfo, sizeof(clientInfo));


///// other function
LRESULT CTest2Dlg::WindowProc(UINT message, WPARAM wParam, LPARAM lParam) 
{
	// TODO: Add your specialized code here and/or call the base class
	if ((message == WM_WINSOCK))
	..... // a case loop here .. ///


	return CDialog::WindowProc(message, wParam, lParam);
}

LRESULT CALLBACK CTest2Dlg::MsgRouter(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	CTest2Dlg* pWindow = (CTest2Dlg*)GetWindowLong( hWnd, GWL_USERDATA );
	return pWindow->WindowProc(message, wParam, lParam);
}

</code>