SerialPort.Read没有抛出TimeoutException

Question

我有以下代码

    private SerialPort _port = null;

    public SerialReader(string portname, int baudrate, Parity parity, int databits, StopBits stopbits, int readTimeoutMs = 10000)
    {
        //Set serial-port
        _port = new SerialPort();
        _port.PortName = portname;
        _port.BaudRate = baudrate;
        _port.Parity = parity;
        _port.DataBits = databits;
        _port.StopBits = stopbits;
        _port.ReadTimeout = readTimeoutMs;
        _port.DataReceived += new SerialDataReceivedEventHandler(SerialPort_DataReceivedNew);
        _port.Open();
    }

    private void SerialPort_DataReceivedNew(object sender, SerialDataReceivedEventArgs e)
    {
        SerialPort port = (SerialPort)sender;
        _buffer = new byte[port.BytesToRead];
        try
        {
            port.Read(_buffer, 0, _buffer.Length);
        }
        catch (System.TimeoutException ex)
        {
            bool doDispose = true;
            if (ReadTimeout != null)
                ReadTimeout(ex, out doDispose);

            if(doDispose)
                this.Dispose();
            return;
        }
        ///////////
    }

如果连接的设备发送数据都工作正常，但是如果我拔掉它，程序会永远等待其他数据，而不会抛出System.TimeoutException（documentation说它应该抛出异常）。

我通过在bool doDispose = true;上放置断点来验证这一点，但从未到达。

程序集编译为＆＃34; Debug＆＃34;。

这是一个错误还是我错过了什么？

修改

有可能没有调用SerialPort_DataReceivedNew，因为实际上没有收到任何数据，如果是这种情况，我该如何捕获错误？

编辑2

为了使它工作，我编辑了这样的代码：

添加了方法BeginGetData和PollSerialPort

    public void BeginGetData()
    {
        _port.Open();
        Thread pollingThread = new System.Threading.Thread(new System.Threading.ThreadStart(PollSerialPort));
        pollingThread.Start();
    }

    private void PollSerialPort()
    {
        while (this.SerialPort_DataReceivedNew()) ;
    }

编辑了SerialPort_DataReceivedNew

    private bool SerialPort_DataReceivedNew()
    {
        _buffer = new byte[_port.BytesToRead];
        try
        {
            if (_port.Read(_buffer, 0, _buffer.Length) == 0)
                _port.Write("\0");
        }
        catch (System.TimeoutException ex)
        {
            bool doDispose = true;
            if (ReadTimeout != null)
                ReadTimeout (this, out doDispose);

            if (doDispose)
            {
                _port.Close();
                return false;
            }
            return true;
        }
        ///////////
    }

在_port.Write("\0");我有TimeoutException