判断是否联网

   #region 是否联网
        private const int INTERNET_CONNECTION_MODEM = 1;
        private const int INTERNET_CONNECTION_LAN = 2;
        [DllImport("winInet.dll ")]
        private static extern bool InternetGetConnectedState(ref   int dwFlag, int dwReserved);
        private void NetConnect()
        {
            int dwFlag = new int();
            if (!InternetGetConnectedState(ref   dwFlag, 0))
            {
                string locPath = AppDomain.CurrentDomain.BaseDirectory;
                this.webView.Navigate(locPath + "html\videoLoc.html");
                //未连网
            }
            else if ((dwFlag & INTERNET_CONNECTION_MODEM) != 0)
            {
                string locPath = AppDomain.CurrentDomain.BaseDirectory;
                this.webView.Navigate(locPath + "html\videoLoc.html");
                //采用调治解调器上网
            }
            else if ((dwFlag & INTERNET_CONNECTION_LAN) != 0)
            {
                string locPath = AppDomain.CurrentDomain.BaseDirectory;
                this.webView.Navigate(locPath + "html\videoLoc.html");
                //采用网卡上网
            }
            else
            {
                string locPath = AppDomain.CurrentDomain.BaseDirectory;
                this.webView.Navigate(locPath + "html\videoLoc.html");
                //未连网
            }
        } 
        #endregion