新人c#小白，各位专家帮忙看下，急！！！

小白本人没学过c#，如果发现低级错误，各位大侠勿嘲笑...
说正题，winform做个设备管理界面，在学习论坛各位大神的帖子中也算是基本完成了开发，但在使用中发现问题，流程是登陆后获取到本机网卡，点击button发送搜索数据包，等待所有设备回应，将所有设备信息显示到listview中，我在存储设备信息时用的是二维string[,], 将string[,]再绘制到listview中，问题出在string[,]经常赋值不上，导致绘制listview时报错“未将对象引用设置到对象的实例”。具体请看代码注释<重点问题>，里边还有两个关于socket的<附加问题>，也请大家帮忙看看，多谢！

         private string[,] scanList = new string[,] { };

        private int scanIndex;

        private static System.Timers.Timer procTimer;

        static Socket mySocket;

        private static IPEndPoint dstPoint;



        private void ToolStripButton5_Click(object sender, EventArgs e)

        {

            DeviceScanPublicValue.searchPort = int.Parse(ToolStripTextBox1.Text);

            DeviceScanPublicValue.devManagePort = 1208;



            /*附加问题1：因为后边有1s的搜索窗口，为防止再次点击按钮触发socket套接字错误，把按钮去使能了，定时器里再使能

             *这里也想请教大家，怎么在发生socket套接字错误时恢复，我现在是一旦发生这种错误就死掉了，只能重新打开应用

             */

            ToolStripButton5.Text = "搜索中...";

            ToolStripButton5.Enabled = false;   



            scanList = new string[511, 11];//最多511个设备

            scanIndex = 0;

            ListView2.Items.Clear();



            byte[] sendData = { 0x44, 0x55, 0x44, 0x55, 0xff, 0xff, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20 };



            //Socket处理

            mySocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

            mySocket.Bind(new IPEndPoint(IPAddress.Parse(DeviceScanPublicValue.localIP), DeviceScanPublicValue.searchPort));



            Thread recvThread = new Thread(ReciveMessage)

            {

                IsBackground = true

            };

            recvThread.Start();

            dstPoint = new IPEndPoint(IPAddress.Broadcast, DeviceScanPublicValue.devManagePort);

            string hostName = Dns.GetHostName();

            mySocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);

            Thread sendThread = new Thread(SendMessage);

            sendThread.Start(sendData);



            //创建一个1000ms定时的定时器，因为不知道有多少设备，给个1s的搜索窗口,定时器结束绘制listview

            procTimer = new System.Timers.Timer(1000);

            procTimer.Elapsed += OnTimedEvent;

            procTimer.AutoReset = false;

            procTimer.Enabled = true;

            procTimer.Start();

        }



        private void SendMessage(object obj)

        {

            byte[] message = (byte[])obj;

            mySocket.SendTo(message, dstPoint);

        }



        private void ReciveMessage()

        {

            EndPoint point = new IPEndPoint(IPAddress.Any, DeviceScanPublicValue.devManagePort);

            Thread.Sleep(50);



            /*附加问题2：搜索时，电脑网卡确实收到4个设备回应的报文，但有时就会出现socket接收不全的情况，比如只解析三个设备

             */

            while (true)

            {

                try

                {

                    Thread.Sleep(50);

                    byte[] buffer = new byte[100];

                    int length = mySocket.ReceiveFrom(buffer, ref point);   //接收数据报

                    SearchMessageProc(buffer);

                }

                catch (Exception)

                {



                }

                finally

                {



                }



            }



        }



        struct DeviceList

        {

            public string type;

            public string name;

            public string location;

            public string logicId;

            public string ip;

            public string mac;

            public string port;

            public string model;

            public string timeModel;

            public string timeIn;

            public string status;

            public string topology;

        };



        private void SearchMessageProc(object obj)

        {

            DeviceList devInfo;

            byte[] message = (byte[])obj;

            if (message[0] == 0x44 && message[1] == 0x55 && message[4] == 0x21)

            {

                /*

                解析报文，得到devInfo，不贴代码了，太长了

                */

                //整合搜索设备信息

                string[] deviceScanInfo = { devInfo.name , devInfo.location , devInfo.logicId   , devInfo.ip     , devInfo.mac    ,

                                            devInfo.port , devInfo.model    , devInfo.timeModel , devInfo.timeIn , devInfo.status , devInfo.topology };





                for (int i = 0; i < 11; i++)

                {

                    /*

                    重点问题：就在这，我测试用四个设备，scanList偶尔就会出现其中一个设备信息为null，但deviceScanInfo是正确的，

                    scanIndex也能加到4，这样就导致后边绘制listview时有null报错,百思不得其解

                    */

                    scanList[scanIndex9000, i] = deviceScanInfo[i];

                    scanIndex++;

                }

            }

        }



        private ListViewItem scanDevList;



        private void OnTimedEvent(object sender, ElapsedEventArgs e)

        {

            ListView2.BeginUpdate();

            for (int i = 0; i < scanIndex; i++)

            {

                scanDevList = new ListViewItem

                {

                    Text = (i + 1).ToString()

                };

                for (int j = 0; j < 11; j++)

                {

                    scanDevList.SubItems.Add(scanList[i, j].ToString());

                }

                ListView2.Items.Add(scanDevList);

                ListView2.Items[i].BackColor = Color.Lavender;

            }



            ListView2.EndUpdate();

            ToolStripButton5.Text = "搜索设备";

            ToolStripButton5.Enabled = true;

            mySocket.Shutdown(SocketShutdown.Both);

            mySocket.Close();

            procTimer.Stop();

        }

多谢各位了