得到代理服务器地址

 INTERNET_PROXY_INFO *pIEinfo = NULL;
 DWORD dwSize = 0;
 BOOL bRet = InternetQueryOption(NULL, INTERNET_OPTION_PROXY, pIEinfo, &dwSize);
 pIEinfo = (INTERNET_PROXY_INFO*)new char[dwSize];
 bRet = InternetQueryOption(NULL, INTERNET_OPTION_PROXY, pIEinfo, &dwSize);