Csharp串口通信

using System.IO.Ports;

var serialPort = new SerialPort
{
    PortName = "COM3",
    BaudRate = 115200,
    DataBits = 8,
    StopBits = StopBits.One,
    Parity = Parity.None,
    Handshake = Handshake.None,
    ReadTimeout = 1000,
    WriteTimeout = 1000,
    Encoding = Encoding.UTF8
};

try
{
    if (!serialPort.IsOpen)
        serialPort.Open();
}
catch (UnauthorizedAccessException)
{
    // 端口被其他程序占用
}
catch (IOException)
{
    // 端口不存在或设备未连接
}

// 使用完毕
if (serialPort.IsOpen)
    serialPort.Close();

serialPort.Dispose();

string[] ports = SerialPort.GetPortNames();
Array.Sort(ports);
foreach (var port in ports)
{
    Console.WriteLine(port);
}

serialPort.WriteLine("AT\r\n");

byte[] frame = { 0x55, 0xAA, 0x01, 0x00, 0x01, 0xFE };
serialPort.Write(frame, 0, frame.Length);

public static byte[] HexStringToBytes(string hex)
{
    hex = hex.Replace(" ", "").Replace("-", "");
    var bytes = new byte[hex.Length / 2];
    for (int i = 0; i < bytes.Length; i++)
        bytes[i] = Convert.ToByte(hex.Substring(i * 2, 2), 16);
    return bytes;
}

// 发送 "55 AA 01 00"
serialPort.Write(HexStringToBytes("55 AA 01 00"), 0, 4);

// 读取指定字节数（阻塞，受 ReadTimeout 限制）
byte[] buffer = new byte[64];
int bytesRead = serialPort.Read(buffer, 0, buffer.Length);

// 读取到指定字符（如换行）
string line = serialPort.ReadLine();

serialPort.DataReceived += SerialPort_DataReceived;

private void SerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
    try
    {
        int count = serialPort.BytesToRead;
        byte[] buffer = new byte[count];
        serialPort.Read(buffer, 0, count);
        OnDataReceived(buffer);
    }
    catch (Exception ex)
    {
        // 记录异常，避免事件线程崩溃
    }
}

private void OnDataReceived(byte[] data)
{
    if (txtLog.InvokeRequired)
    {
        txtLog.BeginInvoke(() => OnDataReceived(data));
        return;
    }

    string hex = BitConverter.ToString(data).Replace("-", " ");
    txtLog.AppendText($"[{DateTime.Now:HH:mm:ss}] RX: {hex}{Environment.NewLine}");
}

private readonly List<byte> _buffer = new();
private const int FrameLength = 8;

private void AppendAndParse(byte[] incoming)
{
    _buffer.AddRange(incoming);

    while (_buffer.Count >= FrameLength)
    {
        byte[] frame = _buffer.GetRange(0, FrameLength).ToArray();
        _buffer.RemoveRange(0, FrameLength);
        ProcessFrame(frame);
    }
}

private void TryParseFrames()
{
    int i = 0;
    while (i + 5 <= _buffer.Count)
    {
        if (_buffer[i] != 0x55 || _buffer[i + 1] != 0xAA)
        {
            i++;
            continue;
        }

        int payloadLen = _buffer[i + 3] | (_buffer[i + 4] << 8);
        int totalLen = 5 + payloadLen + 2;
        if (i + totalLen > _buffer.Count)
            break;

        byte[] frame = _buffer.GetRange(i, totalLen).ToArray();
        _buffer.RemoveRange(0, i + totalLen);
        ProcessFrame(frame);
        i = 0;
    }

    if (i > 0)
        _buffer.RemoveRange(0, i);
}

private readonly StringBuilder _textBuffer = new();

private void AppendTextData(byte[] data)
{
    _textBuffer.Append(Encoding.UTF8.GetString(data));
    string content = _textBuffer.ToString();
    int index;
    while ((index = content.IndexOf("\r\n")) >= 0)
    {
        string line = content[..index];
        ProcessLine(line);
        content = content[(index + 2)..];
    }
    _textBuffer.Clear();
    _textBuffer.Append(content);
}

public async Task<byte[]> ReadAsync(int length, CancellationToken token)
{
    byte[] buffer = new byte[length];
    int offset = 0;

    while (offset < length)
    {
        int read = await serialPort.BaseStream.ReadAsync(
            buffer, offset, length - offset, token);
        if (read == 0)
            throw new EndOfStreamException("串口已关闭");
        offset += read;
    }
    return buffer;
}

using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(3));
try
{
    byte[] response = await ReadAsync(64, cts.Token);
}
catch (OperationCanceledException)
{
    // 超时处理
}

public class SerialPortService : IDisposable
{
    private SerialPort? _port;

    public event Action<byte[]>? DataReceived;
    public event Action<string>? ErrorOccurred;

    public bool IsOpen => _port?.IsOpen == true;

    public void Open(string portName, int baudRate)
    {
        Close();
        _port = new SerialPort(portName, baudRate, Parity.None, 8, StopBits.One)
        {
            ReadTimeout = 500,
            WriteTimeout = 500
        };
        _port.DataReceived += OnDataReceived;
        _port.Open();
    }

    public void Send(byte[] data) => _port?.Write(data, 0, data.Length);

    private void OnDataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        try
        {
            int count = _port!.BytesToRead;
            byte[] buf = new byte[count];
            _port.Read(buf, 0, count);
            DataReceived?.Invoke(buf);
        }
        catch (Exception ex)
        {
            ErrorOccurred?.Invoke(ex.Message);
        }
    }

    public void Close()
    {
        if (_port == null) return;
        _port.DataReceived -= OnDataReceived;
        if (_port.IsOpen) _port.Close();
        _port.Dispose();
        _port = null;
    }

    public void Dispose() => Close();
}

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

class Program
{
    static void Main()
    {
        var ports = SerialPort.GetPortNames();
        if (ports.Length == 0)
        {
            Console.WriteLine("未找到串口");
            return;
        }

        using var sp = new SerialPort(ports[0], 115200)
        {
            Encoding = Encoding.UTF8,
            NewLine = "\r\n"
        };

        sp.DataReceived += (_, _) =>
        {
            string data = sp.ReadExisting();
            Console.WriteLine($"RX: {data}");
        };

        sp.Open();
        Console.WriteLine($"已打开 {sp.PortName}，输入内容回车发送，输入 exit 退出");

        while (true)
        {
            string? input = Console.ReadLine();
            if (input == "exit") break;
            sp.WriteLine(input);
        }
    }
}