基于C#实现多线程串口通信

一、核心架构设计

主线程
SerialPortManager
接收线程
发送线程
数据缓冲队列
数据处理线程

二、关键代码实现

1. 串口管理类（线程安全封装）

csharp 复制代码

using System.IO.Ports;
using System.Threading;
using System.Collections.Concurrent;

public class SerialPortManager : IDisposable
{
    private SerialPort _serialPort;
    private Thread _readThread;
    private Thread _writeThread;
    private ConcurrentQueue<byte[]> _dataQueue = new ConcurrentQueue<byte[]>();
    private AutoResetEvent _writeEvent = new AutoResetEvent(false);
    private SemaphoreSlim _serialLock = new SemaphoreSlim(1, 1);

    public event Action<byte[]> DataReceived;

    public SerialPortManager(string portName, int baudRate)
    {
        InitializePort(portName, baudRate);
        StartThreads();
    }

    private void InitializePort(string portName, int baudRate)
    {
        _serialPort = new SerialPort(portName, baudRate)
        {
            Parity = Parity.None,
            DataBits = 8,
            StopBits = StopBits.One,
            ReadTimeout = 500,
            WriteTimeout = 500
        };
        
        _serialPort.DataReceived += (s, e) => 
        {
            var buffer = new byte[_serialPort.BytesToRead];
            _serialPort.Read(buffer, 0, buffer.Length);
            _dataQueue.Enqueue(buffer);
            DataReceived?.Invoke(buffer);
        };
    }

    private void StartThreads()
    {
        _readThread = new Thread(ProcessIncomingData);
        _writeThread = new Thread(ProcessOutgoingData);
        _readThread.Start();
        _writeThread.Start();
    }

    public async Task SendDataAsync(byte[] data)
    {
        await _serialLock.WaitAsync();
        try
        {
            _writeEvent.Set();
            _serialPort.Write(data, 0, data.Length);
        }
        finally
        {
            _serialLock.Release();
        }
    }

    private void ProcessIncomingData()
    {
        while (!_serialPort.IsOpen) Thread.Sleep(100);
        
        while (true)
        {
            if (_dataQueue.TryDequeue(out var data))
            {
                // 数据解析逻辑
                ParseData(data);
            }
            Thread.Sleep(10);
        }
    }

    private void ProcessOutgoingData()
    {
        while (true)
        {
            _writeEvent.WaitOne();
            // 发送队列处理逻辑
        }
    }

    private void ParseData(byte[] data)
    {
        // 实现具体协议解析
    }

    public void Dispose()
    {
        _serialLock.Dispose();
        _writeEvent.Dispose();
        _serialPort?.Close();
        _serialPort?.Dispose();
    }
}

三、线程同步机制

1. 双缓冲队列设计

csharp 复制代码

private ConcurrentQueue<byte[]> _readBuffer = new ConcurrentQueue<byte[]>();
private ConcurrentQueue<byte[]> _processBuffer = new ConcurrentQueue<byte[]>();

// 数据接收线程
void ReceiveThread()
{
    while (true)
    {
        if (_serialPort.BytesToRead > 0)
        {
            var buffer = new byte[_serialPort.BytesToRead];
            _serialPort.Read(buffer, 0, buffer.Length);
            _readBuffer.Enqueue(buffer);
        }
        Thread.Sleep(1);
    }
}

// 数据处理线程
void ProcessThread()
{
    while (true)
    {
        if (_readBuffer.TryDequeue(out var data))
        {
            _processBuffer.Enqueue(ProcessData(data));
        }
    }
}

2. 异步读写实现

csharp 复制代码

public async Task<byte[]> ReadAsync(CancellationToken ct)
{
    await _serialLock.WaitAsync(ct);
    try
    {
        var buffer = new byte[1024];
        int bytesRead = await _serialPort.BaseStream.ReadAsync(buffer, 0, buffer.Length, ct);
        Array.Resize(ref buffer, bytesRead);
        return buffer;
    }
    finally
    {
        _serialLock.Release();
    }
}

public async Task WriteAsync(byte[] data, CancellationToken ct)
{
    await _serialLock.WaitAsync(ct);
    try
    {
        await _serialPort.BaseStream.WriteAsync(data, 0, data.Length, ct);
    }
    finally
    {
        _serialLock.Release();
    }
}

四、异常处理

1. 异常捕获框架

csharp 复制代码

public void SafeWrite(byte[] data)
{
    try
    {
        _serialLock.Wait();
        _serialPort.Write(data, 0, data.Length);
    }
    catch (TimeoutException ex)
    {
        HandleTimeout();
    }
    catch (IOException ex)
    {
        HandleDeviceDisconnect();
    }
    finally
    {
        _serialLock.Release();
    }
}

2. 自动重连机制

csharp 复制代码

private void HandleDeviceDisconnect()
{
    _serialLock.Wait();
    try
    {
        if (_serialPort.IsOpen) _serialPort.Close();
        Thread.Sleep(1000);
        ReinitializePort();
    }
    finally
    {
        _serialLock.Release();
    }
}

private void ReinitializePort()
{
    InitializePort(_config.PortName, _config.BaudRate);
    StartThreads();
}

参考代码 c#编写串口通讯代码多线程 www.youwenfan.com/contentcsr/111962.html

五、性能优化

1. 内存池管理

csharp 复制代码

private ObjectPool<byte[]> _bufferPool = new ObjectPool<byte[]>(() => new byte[1024], 10);

byte[] GetBuffer() => _bufferPool.Get();
void ReturnBuffer(byte[] buffer) => _bufferPool.Return(buffer);

2. 批量数据处理

csharp 复制代码

public void ProcessBatchData(IEnumerable<byte[]> dataArray)
{
    Parallel.ForEach(dataArray, data =>
    {
        var parsed = ParseData(data);
        lock (_processedData)
        {
            _processedData.Add(parsed);
        }
    });
}

六、完整使用示例

csharp 复制代码

var manager = new SerialPortManager("COM3", 115200);

// 异步发送数据
await manager.SendDataAsync(Encoding.UTF8.GetBytes("Hello"));

// 接收回调处理
manager.DataReceived += (data) => 
{
    var text = Encoding.UTF8.GetString(data);
    Console.WriteLine($"Received: {text}");
};

// 后台数据处理
Task.Run(() => 
{
    while (true)
    {
        if (manager.TryDequeueProcessedData(out var data))
        {
            UpdateUI(data);
        }
    }
});

七、调试与监控

1. 日志记录

csharp 复制代码

public void LogCommunication(string message)
{
    lock (_logLock)
    {
        File.AppendAllText("com_log.txt", 
            $"{DateTime.Now:HH:mm:ss.fff} - {message}{Environment.NewLine}");
    }
}

2. 实时状态监控

csharp 复制代码

public class SerialStatus
{
    public int BytesSent { get; private set; }
    public int BytesReceived { get; private set; }
    
    public void IncrementSent(int count) => BytesSent += count;
    public void IncrementReceived(int count) => BytesReceived += count;
}

八、扩展功能实现

1. 协议解析器

csharp 复制代码

public class ModbusParser
{
    public static Dictionary<byte, ushort> ParseFrame(byte[] data)
    {
        // 实现Modbus RTU协议解析
        return new Dictionary<byte, ushort>();
    }
}

2. 加密传输

csharp 复制代码

public class SecureSerialPort
{
    private Aes _aes = Aes.Create();

    public byte[] Encrypt(byte[] data)
    {
        using (var encryptor = _aes.CreateEncryptor())
        using (var ms = new MemoryStream())
        {
            cs.Write(data, 0, data.Length);
            return ms.ToArray();
        }
    }
}

九、最佳实践建议

线程模型选择
- 优先使用Task替代传统Thread
- 高频数据采用BlockingCollection实现生产者-消费者模式

资源管理规范

csharp 复制代码

using (var manager = new SerialPortManager())
{
    // 自动释放资源
}

性能监控指标
- 串口缓冲区占用率
- 数据处理延迟
- 异常发生频率