ADXL335 C#

1.cs

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.Ports;
using System.Threading;

namespace ADXL335
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private SerialPort serial_port_;
        private Thread     thread_;

        private void refresh_button_Click(object sender, EventArgs e)
        {
            portlist_comboBox.Items.Clear();
            foreach (string s in SerialPort.GetPortNames())
            {
                portlist_comboBox.Items.Add(s);
            }
        }

        private void connect_button_Click(object sender, EventArgs e)
        {
            if ("Connect" == connect_button.Text)
            {
                if (-1 == portlist_comboBox.SelectedIndex)
                {
                    MessageBox.Show("Select com port");
                    return;
                }
                string port_name = portlist_comboBox.SelectedItem.ToString();
                serial_port_ = new SerialPort(port_name, 9600);

                serial_port_.Open();
                thread_ = new Thread(read_serial_port);
                thread_.Start();

                connect_button.Text = "Disconnect";
            }
            else
            {
                try
                {
                    thread_.Abort();
                    serial_port_.Close();
                }
                catch
                {
                }
                connect_button.Text = "Connect";
            }
        }

        private void read_serial_port()
        {
            while (serial_port_.IsOpen)
            {
                try
                {
                    string str = serial_port_.ReadLine();
                    set_axis(str);
                }
                catch (TimeoutException) { }
            }
        }

        delegate void SetTextCallback(string newText);
        private string str_;

        private void set_axis(string text)
        {
            if (this.X_progressBar.InvokeRequired)
            {
                SetTextCallback d = new SetTextCallback(set_axis);
                this.Invoke(d, new object[] { text });
            }
            else
            {
                str_ += text;
                int i1 = str_.IndexOf("BEG");
                int i2 = str_.IndexOf("BEG", 1 + i1);
                if ((-1 != i1) && (-1 != i2))
                {
                    string current = str_.Substring(0, i2);
                    current = current.Substring(current.IndexOf("BEG"));
                    str_ = str_.Substring(i2);

                    int beg_index = current.IndexOf("BEG");
                    int x_index = current.IndexOf("X");
                    int y_index = current.IndexOf("Y");
                    int z_index = current.IndexOf("Z");
                    
                    if ((0 != beg_index) || (3 != x_index) || (-1 == y_index) || (-1 == z_index))
                    {
                        MessageBox.Show("Error " + current + ", beg_index = " + beg_index.ToString() + ", x_index = " + x_index.ToString() + ", y_index = " + y_index.ToString() + ", z_index = " + z_index.ToString());
                        return;
                    }

                    int x = Convert.ToInt32(current.Substring(x_index + 1, y_index - x_index - 1));
                    int y = Convert.ToInt32(current.Substring(y_index + 1, z_index - y_index - 1));
                    int z = Convert.ToInt32(current.Substring(z_index + 1));

                    if (x > X_progressBar.Maximum) x = X_progressBar.Maximum;
                    if (y > Y_progressBar.Maximum) y = Y_progressBar.Maximum;
                    if (z > Z_progressBar.Maximum) z = Z_progressBar.Maximum;

                    if (x < X_progressBar.Minimum) x = X_progressBar.Minimum;
                    if (y < Y_progressBar.Minimum) y = Y_progressBar.Minimum;
                    if (z < Z_progressBar.Minimum) z = Z_progressBar.Minimum;

                    X_progressBar.Value = x;
                    Y_progressBar.Value = y;
                    Z_progressBar.Value = z;
                }
            }
        }

        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            try
            {
                serial_port_.Close();
            }
            catch
            {
            }
        }
    }
}