读取本地IP地址和子网页码

  #region 读取本地IP地址和子网页码
            //读取本地IP地址和子网页码
            NetworkInterface[] nics = NetworkInterface.GetAllNetworkInterfaces();
            foreach (NetworkInterface adapter in nics)
            {
                if (adapter.NetworkInterfaceType.ToString().Equals("Ethernet"))
                {
                    //adapter.Name;     //网卡适配名称：“本地连接”
                    //adapter.Description;   //适配器描述信息
                    IPInterfaceProperties ip = adapter.GetIPProperties();     //IP配置信息

                    if (ip.UnicastAddresses.Count > 0)
                    {
                        string localip = ip.UnicastAddresses[1].Address.ToString();   //IP地址
                        txtIP.Text = localip;
                        string localcode = ip.UnicastAddresses[1].IPv4Mask.ToString();  //子网掩码
                        txtZWym.Text = localcode;

                    }
                    if (ip.GatewayAddresses.Count > 0)
                    {
                        string net = ip.GatewayAddresses[0].Address.ToString();   //默认网关
                        txtWg.Text = net;
                    }

                    if (ip.DnsAddresses.Count > 0)
                    {
                        ip.DnsAddresses[0].ToString();       //首选DNS服务器地址
                        if (ip.DnsAddresses.Count > 1)
                            ip.DnsAddresses[1].ToString();  //备用DNS服务器地址
                        //MessageBox.Show(" ip.DnsAddresses[0].ToString();:" + ip.DnsAddresses[0].ToString());
                    }
                }
            }
            #endregion

 方法二：上面的方法有时候读不出来子网掩码，需要如下方法：

  ManagementClass mc = new ManagementClass("Win32_NetworkAdapterConfiguration");
            ManagementObjectCollection nics = mc.GetInstances();
            foreach (ManagementObject nic in nics)
            {
                if (Convert.ToBoolean(nic["ipEnabled"]) == true)
                {
                    string mac = nic["MacAddress"].ToString();//Mac地址

                    string ip = (nic["IPAddress"] as String[])[0];//IP地址
                    txtIP.Text = ip;
                    string ipsubnet = (nic["IPSubnet"] as String[])[0];//子网掩码
                    txtZWym.Text = ipsubnet;
                    string ipgateway = (nic["DefaultIPGateway"] as String[])[0];//默认网关
                    txtWg.Text = ipgateway;
                }
            }