#region 通过oid字符数组获得相应的值
        public static Dictionary<string, string> getOIDValue(string host,string[] oid) {
            Dictionary<string, string> dic = new Dictionary<string, string>();

            OctetString community = new OctetString("public");
            AgentParameters param = new AgentParameters(community);
            param.Version = SnmpVersion.Ver1;
            IpAddress agent = new IpAddress(host);
            UdpTarget target = new UdpTarget((IPAddress)agent,161,2000,1);
            Pdu pdu = new Pdu(PduType.Get);

            foreach (String singleOid in oid)
            {
                pdu.VbList.Add(singleOid);
            }

            SnmpV1Packet result = (SnmpV1Packet)target.Request(pdu,param);
            if (result != null) {
                if (result.Pdu.ErrorStatus == 0) {
                    for (int i = 0; i < result.Pdu.VbList.Count; i++)
                    {
                        dic.Add(result.Pdu.VbList[i].Oid.ToString()+"-"+i, result.Pdu.VbList[i].Value.ToString()); 
                    }
                }
            }
            target.Close();

            return dic;
        }
        #endregion

#region 通过snmpwalk返回oid根下面的所有值
        public static Dictionary<string, string> getWalkValue(string host, string irootOid)
        {
            Dictionary<string, string> dic = new Dictionary<string, string>();
            // SNMP community name   
            OctetString community = new OctetString("public");

            // Define agent parameters class   
            AgentParameters param = new AgentParameters(community);
            // Set SNMP version to 2 (GET-BULK only works with SNMP ver 2 and 3)   
            param.Version = SnmpVersion.Ver2;
            // Construct the agent address object   
            // IpAddress class is easy to use here because   
            //  it will try to resolve constructor parameter if it doesn‘t   
            //  parse to an IP address   
            IpAddress agent = new IpAddress(host);

            // Construct target   
            UdpTarget target = new UdpTarget((IPAddress)agent, 161, 2000, 1);

            // Define Oid that is the root of the MIB   
            //  tree you wish to retrieve   
            Oid rootOid = new Oid(irootOid); // ifDescr   

            // This Oid represents last Oid returned by   
            //  the SNMP agent   
            Oid lastOid = (Oid)rootOid.Clone();

            // Pdu class used for all requests   
            Pdu pdu = new Pdu(PduType.GetBulk);

            // In this example, set NonRepeaters value to 0   
            pdu.NonRepeaters = 0;
            // MaxRepetitions tells the agent how many Oid/Value pairs to return   
            // in the response.   
            pdu.MaxRepetitions = 5;

            // Loop through results   
            while (lastOid != null)
            {
                // When Pdu class is first constructed, RequestId is set to 0   
                // and during encoding id will be set to the random value   
                // for subsequent requests, id will be set to a value that   
                // needs to be incremented to have unique request ids for each   
                // packet   
                if (pdu.RequestId != 0)
                {
                    pdu.RequestId += 1;
                }
                // Clear Oids from the Pdu class.   
                pdu.VbList.Clear();
                // Initialize request PDU with the last retrieved Oid   
                pdu.VbList.Add(lastOid);
                // Make SNMP request   
                SnmpV2Packet result = (SnmpV2Packet)target.Request(pdu, param);
                // You should catch exceptions in the Request if using in real application.   

                // If result is null then agent didn‘t reply or we couldn‘t parse the reply.   
                if (result != null)
                {
                    // ErrorStatus other then 0 is an error returned by    
                    // the Agent - see SnmpConstants for error definitions   
                    if (result.Pdu.ErrorStatus == 0)
                    {
                        // Walk through returned variable bindings   
                        foreach (Vb v in result.Pdu.VbList)
                        {
                            // Check that retrieved Oid is "child" of the root OID   
                            if (rootOid.IsRootOf(v.Oid))
                            {
                                dic.Add(v.Oid.ToString(), v.Value.ToString());
                            }
                            else
                            {
                                // we have reached the end of the requested   
                                // MIB tree. Set lastOid to null and exit loop   
                                lastOid = null;
                            }
                        }
                    }
                }
            }
            target.Close();
            return dic;
        }
        #endregion