DataReceivedHandler永远不会触发？

Question

我正在开发一个项目，它将从COM端口读取数据，将其保存到数据表中，在图表中显示，并允许通过csv保存/加载数据。到目前为止，已实现串行通信和文件操作。

目前我正在使用arduino对其进行测试，该代码发送<uint16>（包括'＆lt;＆gt;'符号，uint16为任意数字）。

不幸的是，DataRecievedHandler似乎永远不会被调用，我已经通过在接收到数据时将其打印到GUI中的文本框进行了测试。 Arduino的TX灯在发送数据时正常闪烁，并与arduino串行监视器配合使用。 COM端口似乎连接正常，因为它使串行线路忙，因此arduino软件无法同时连接到它。

关于我哪里出错的任何想法？我觉得这一定是蠢事。为了以防万一，我附上了完整的代码。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.IO.Ports;
using System.Threading;
using System.Text.RegularExpressions;

namespace FieldProbe
{
    public partial class MainForm : Form
    {
        SerialPort _port = new SerialPort();

        DataTable dt = new DataTable(); //set up datatable to hold output
        int numSamples = 0;

        public MainForm()
        {
            InitializeComponent();
        }

        private void MainForm_Load(object sender, EventArgs e)
        {
            var ports = SerialPort.GetPortNames();  //get list of ports connected to PC
            cmbSerialPorts.DataSource = ports;      //use list of ports as combobox options
            _port.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandler);  //create pointer to datareceived event handler

            dt.Clear(); //Clear datatable on start
            dt.Columns.Add("index", typeof(int));           //index
            dt.Columns.Add("dutyCycle", typeof(float));     //0.5 means equal on/off, 1.0 means permanently on
            dt.Columns.Add("frequency", typeof(float));     //probe can go from 40MHz to 10GHz
            dt.Columns.Add("distance", typeof(float));      //antenna to radiator distance in metres (usually 1m)
            dt.Columns.Add("pulseWidth", typeof(float));    //calculated from duty cycle and frequency
            dt.Columns.Add("level", typeof(int));           //output in V/m

            chChart.Series["series1"].XValueMember = "level";
            chChart.Series["series1"].YValueMembers = "index";
            chChart.DataSource = dt;
            chChart.DataBind();
        }

        private void btnConnect_Click(object sender, EventArgs e)
        {
            if (btnConnect.Text == "Connect")   //if user clicks connect button
            {

                if (cmbSerialPorts.SelectedIndex > -1)  //if port valid
                {
                    MessageBox.Show(String.Format("You selected port '{0}'", cmbSerialPorts.SelectedItem));
                    Connect(cmbSerialPorts.SelectedItem.ToString());    //go to connect function
                }
                else
                {
                    MessageBox.Show("Please select a port first");
                }
            }
            else    //if user clicks disconnect button
            {
                btnConnect.Text = "Connect";
                _port.Close();
            }

        }

        private void Connect(string portName)
        {
            _port = new SerialPort(portName);   //set up serial port using static values (make editable in a config file?)
            if (!_port.IsOpen)
            {
                _port.BaudRate = 9600;  //CHANGE ME AFTER ARDUINO TESTING!!!!!!!!!!!!!!
                _port.DataBits = 8;
                _port.StopBits = StopBits.One;
                _port.Parity = Parity.None;
                _port.Handshake = Handshake.None;
                _port.RtsEnable = true; //CHANGE ME AFTER ARDUINO TESTING!!!!!!!!!!!!!!
                _port.DtrEnable = true; //CHANGE ME AFTER ARDUINO TESTING!!!!!!!!!!!!!!
                try
                {
                    _port.Open();   //connect to port
                    btnConnect.Text = "Disconnect";
                }
                catch
                {
                    MessageBox.Show("ERROR: Port invalid or in use!");
                    btnConnect.Text = "Connect";
                }
            }
        }

        private void DataReceivedHandler(object sender, SerialDataReceivedEventArgs e)
        {
            SerialPort sp = (SerialPort)sender;
            string indata = sp.ReadExisting();  //read data from port
            string indataString = Regex.Match(indata, @"\d+").Value;    //extract number (still a string)
            int indataInt = Int32.Parse(indataString);      //convert string to int

            teIncomingData.AppendText(indata);  //append number to text box for testing
            teIncomingData.AppendText("test1"); //show text in textbox if this function is called

            numSamples++;

            var pulseWidth = nudDutyCycle.Value / (nudFrequency.Value * 100);

            object[] o = {numSamples, nudDutyCycle.Value, nudFrequency.Value, nudDistance.Value, pulseWidth, indataInt};
            dt.Rows.Add(o);
            chChart.DataBind();
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            SaveFileDialog saveFileDialog1 = new SaveFileDialog();
            saveFileDialog1.Filter = "csv files (*.csv)|*.csv*";
            saveFileDialog1.RestoreDirectory = true;
            saveFileDialog1.DefaultExt = "csv";
            saveFileDialog1.AddExtension= true;

            if (saveFileDialog1.ShowDialog() == DialogResult.OK)
            {
                File.WriteAllText(saveFileDialog1.FileName, dtToCSV());
            }
        }

        private string dtToCSV()
        {
            string file = "";

            foreach (DataColumn col in dt.Columns)
                file = string.Concat(file, col.ColumnName, ",");

            file = file.Remove(file.LastIndexOf(','), 1);
            file = string.Concat(file, "\r\n");

            foreach (DataRow row in dt.Rows)
            {
                foreach (object item in row.ItemArray)
                    file = string.Concat(file, item.ToString(), ",");

                file = file.Remove(file.LastIndexOf(','), 1);
                file = string.Concat(file, "\r\n");
            }

            return file;
        }

        public void saveFileDialog1_FileOk(object sender, CancelEventArgs e)
        {   //do not delete me, this needs to exist for some reason for saving to work
        }
    }
}