请用C#实现下述功能假设你是激光雷达厂家激光雷达为客户端天线为服务端两个设备采用TCP连接传输数据通信采用应答方式发送方每发一帧需等待对方确认帧如果没有应答则进行重发重发间隔120ms最大重发次数为3次。通讯的数据帧格式为：STX VER LEN CMD DATA CRC STX为帧开始标志2字节取值为FFFFHVER为协议版本号1字节当前版本为00HLEN为CMD+DATA域的长度4字节CMD为

以下是使用C#实现通信功能的示例代码：

using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;

public class LaserRadar
{
    private const int MaxRetries = 3;
    private const int RetryInterval = 120;

    private TcpClient client;
    private NetworkStream stream;
    private bool isConnected;

    public void Connect(string ipAddress, int port)
    {
        try
        {
            client = new TcpClient();
            client.Connect(ipAddress, port);
            stream = client.GetStream();
            isConnected = true;
        }
        catch (Exception ex)
        {
            Console.WriteLine("Failed to connect: " + ex.Message);
            isConnected = false;
        }
    }

    public void Disconnect()
    {
        if (isConnected)
        {
            stream.Close();
            client.Close();
            isConnected = false;
        }
    }

    public bool SendFrame(Frame frame)
    {
        if (!isConnected)
        {
            Console.WriteLine("Not connected to the server.");
            return false;
        }

        byte[] data = frame.ToBytes();
        int retries = 0;

        while (retries < MaxRetries)
        {
            try
            {
                stream.Write(data, 0, data.Length);
                stream.Flush();

                // Wait for the response
                byte[] response = new byte[1024];
                int bytesRead = stream.Read(response, 0, response.Length);

                if (bytesRead > 0)
                {
                    Frame responseFrame = Frame.FromBytes(response);
                    if (responseFrame != null && responseFrame.IsAck())
                    {
                        return true;
                    }
                }

                retries++;
                Thread.Sleep(RetryInterval);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Failed to send frame: " + ex.Message);
                retries++;
                Thread.Sleep(RetryInterval);
            }
        }

        Console.WriteLine("Failed to receive ACK after multiple retries.");
        return false;
    }
}

public class Frame
{
    private const ushort StartFlag = 0xFFFF;

    public byte Version { get; set; }
    public uint Length { get; set; }
    public byte Command { get; set; }
    public string Data { get; set; }
    public ushort CRC { get; set; }

    public Frame() { }

    public Frame(byte version, uint length, byte command, string data)
    {
        Version = version;
        Length = length;
        Command = command;
        Data = data;
        CRC = CalculateCRC();
    }

    public bool IsAck()
    {
        return (Command & 0x80) == 0x80;
    }

    public byte[] ToBytes()
    {
        byte[] dataBytes = Encoding.ASCII.GetBytes(Data);
        ushort crc = CalculateCRC();

        using (MemoryStream ms = new MemoryStream())
        using (BinaryWriter writer = new BinaryWriter(ms))
        {
            writer.Write(StartFlag);
            writer.Write(Version);
            writer.Write(Length);
            writer.Write(Command);
            writer.Write(dataBytes);
            writer.Write(crc);

            return ms.ToArray();
        }
    }

    public static Frame FromBytes(byte[] bytes)
    {
        using (MemoryStream ms = new MemoryStream(bytes))
        using (BinaryReader reader = new BinaryReader(ms))
        {
            ushort startFlag = reader.ReadUInt16();
            if (startFlag != StartFlag)
            {
                Console.WriteLine("Invalid start flag.");
                return null;
            }

            byte version = reader.ReadByte();
            uint length = reader.ReadUInt32();
            byte command = reader.ReadByte();
            byte[] dataBytes = reader.ReadBytes((int)length - 5);
            ushort crc = reader.ReadUInt16();

            string data = Encoding.ASCII.GetString(dataBytes);

            Frame frame = new Frame(version, length, command, data);
            if (frame.CalculateCRC() != crc)
            {
                Console.WriteLine("Invalid CRC.");
                return null;
            }

            return frame;
        }
    }

    private ushort CalculateCRC()
    {
        byte[] bytes = Encoding.ASCII.GetBytes(Version.ToString("X2") + Length.ToString("X8") + Command.ToString("X2") + Data);
        ushort crc = 0xFFFF;

        foreach (byte b in bytes)
        {
            crc ^= (ushort)(b << 8);

            for (int i = 0; i < 8; i++)
            {
                if ((crc & 0x8000) != 0)
                {
                    crc = (ushort)((crc << 1) ^ 0x1021);
                }
                else
                {
                    crc <<= 1;
                }
            }
        }

        return crc;
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        LaserRadar laserRadar = new LaserRadar();
        laserRadar.Connect("127.0.0.1", 1234);

        Frame frame = new Frame(0x00, 13, 0x00, "{\"type\":\"ask\",\"value\":\"{\\\"errCode\\\":1,\\\"errDesc\\\":\\\"the 2nd parameter is wrong\\\"}\"}");
        if (laserRadar.SendFrame(frame))
        {
            Console.WriteLine("Frame sent successfully.");
        }
        else
        {
            Console.WriteLine("Failed to send frame.");
        }

        laserRadar.Disconnect();
    }
}

请注意，上述示例代码仅实现了通信功能的基本框架，具体的数据处理和业务逻辑需要根据实际需求进行补充和修改