JT809协议交通809协议简单实现c#代码

以下是一个简单的C#代码示例，可用于JT809协议数据的解析和生成：

using System;
using System.IO;
using System.Text;

namespace JT809Protocol
{
    public class JT809Message
    {
        public uint MsgLength { get; set; }
        public uint MsgSn { get; set; }
        public ushort MsgId { get; set; }
        public byte[] MsgBody { get; set; }
        public uint CRC32 { get; set; }

        public void Serialize(Stream stream)
        {
            BinaryWriter writer = new BinaryWriter(stream);
            writer.Write(MsgLength);
            writer.Write(MsgSn);
            writer.Write(MsgId);
            writer.Write(MsgBody);
            writer.Write(CRC32);
        }

        public void Deserialize(Stream stream)
        {
            BinaryReader reader = new BinaryReader(stream);
            MsgLength = reader.ReadUInt32();
            MsgSn = reader.ReadUInt32();
            MsgId = reader.ReadUInt16();
            MsgBody = reader.ReadBytes((int)(MsgLength - 12));
            CRC32 = reader.ReadUInt32();
        }

        public static uint CalculateCRC32(byte[] data, uint offset, uint length)
        {
            uint[] table = new uint[] {
                0x00000000, 0x04C11DB7, 0x09823B6E, 0x0D4326D9,
                0x130476DC, 0x17C56B6B, 0x1A864DB2, 0x1E475005,
                // 略...
                0xF40E3585, 0xF060CF14, 0xFED41B76, 0xFA0F3D63,
                0xFDBAACF8, 0xFFCCBBE1, 0xFF95C5F4, 0xFF2A7604,
            };

            uint crc = 0xFFFFFFFF;
            for (uint i = offset; i < offset + length; i++)
            {
                crc = (crc << 8) ^ table[((crc >> 24) & 0xFF) ^ data[i]];
            }
            return ~crc;
        }
    }

    public class JT809Serializer
    {
        public static byte[] Serialize(JT809Message message)
        {
            MemoryStream stream = new MemoryStream();
            message.Serialize(stream);
            byte[] data = stream.ToArray();
            message.CRC32 = JT809Message.CalculateCRC32(data, 0, (uint)data.Length);
            stream.Seek(0, SeekOrigin.Begin);
            message.Serialize(stream);
            return stream.ToArray();
        }

        public static JT809Message Deserialize(byte[] data)
        {
            JT809Message message = new JT809Message();
            MemoryStream stream = new MemoryStream(data);
            message.Deserialize(stream);
            uint crc = JT809Message.CalculateCRC32(data, 0, (uint)data.Length - 4);
            if (crc != message.CRC32)
            {
                throw new Exception("CRC32 check failed");
            }
            return message;
        }
    }
}

上述代码中，`JT809Message`类表示一个JT809消息，包括消息头和消息体。`Serialize`方法用于将消息序列化为字节数组，`Deserialize`方法用于从字节数组反序列化出消息。`CalculateCRC32`方法用于计算CRC32校验码。

`JT809Serializer`类是一个辅助类，用于将消息序列化为字节数组和从字节数组反序列化出消息。它使用`JT809Message`类的`Serialize`和`Deserialize`方法实现这些功能，并在序列化时计算CRC32校验码，反序列化时验证CRC32校验码是否正确。

请注意，这只是一个简单的示例代码，实际使用中可能需要根据具体的需求进行修改和扩展。