NetworkInformation.NetworkStatusChanged += NetworkInformation_NetworkStatusChanged; //网络连接发生变化时触发

        private bool IsConnectedToInternet()//有无网络连接判断

        {

            bool connected = false;

            ConnectionProfile Conpro = NetworkInformation.GetInternetConnectionProfile();

            if (Conpro != null)

            {

                NetworkConnectivityLevel network = Conpro.GetNetworkConnectivityLevel();

                connected = network == NetworkConnectivityLevel.InternetAccess;

            }

            return connected;

        }/* 何问起 hovertree.com */