Read the IP and device information of the switch node in the XML file, Ping the device, and the exception is displayed in the list

        private void button1_Click(object sender, EventArgs e)
        {
            treeView1.Nodes.Clear();
            Ping pingSender = new Ping();
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load("ip.xml");
            XmlNodeList xnList = xmlDoc.SelectNodes("//switch");
            foreach (XmlNode xn in xnList)
            {
               string switch_ip = (xn.SelectSingleNode("ip")).InnerText;
               string switch_info = xn.SelectSingleNode("info").InnerText;
               PingReply reply = pingSender.Send(switch_ip, 120);// The first parameter is zero ip Address , The second parameter is ping Time for  
               if (reply.Status != IPStatus.Success)
               {
                    treeView1.Nodes.Add(switch_ip + " ( " + switch_info + ")");
               }
            }

        }

xml The content of the document looks like ：

<?xml version="1.0" encoding="GB2312" standalone="yes" ?>
<company>    
 <switch>
  <ip>192.168.10.1</ip>
  <info>H3C 5500 Switch </info>
 </switch>
 <switch>
  <ip>192.168.10.2</ip>
  <info>H3C-S3100 Switch </info>
 </switch>

</company>