用INET(CHttpFile)下载有重定向链接时获取最终URL的方法.

CString GetRedirectedURL(CString p_URL)
{
	CString szFinalUrl;
	CInternetSession _session;
	CStdioFile * pcsf;
	CHttpFile * pchf;
	try {
		pcsf = _session.OpenURL(p_URL, INTERNET_FLAG_TRANSFER_BINARY);
		CHttpFile * pchf = (CHttpFile*)pcsf;
		CHAR buf[2048] = {0};
		DWORD dwOptionReaded = 0;
		pchf->QueryOption(INTERNET_OPTION_URL, buf, dwOptionReaded);
		szFinalUrl.Format(_T("%s"), buf);
	}
	catch(...) {
		_session.Close();
		pcsf->Close(), delete pcsf, pcsf = 0, pchf = 0;
	}
	_session.Close();
	pcsf->Close(), delete pcsf, pcsf = 0, pchf = 0;
	return szFinalUrl;
}