C# Serial Communication (RS-232)

[창공]

// https://youtu.be/Xqx6a_aGlMU

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using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.IO.Ports;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

namespace SerialComm

{

    public partial class Form1 : Form

    {

        System.IO.Ports.SerialPort serialPort = new System.IO.Ports.SerialPort();

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            string[] Comlist = System.IO.Ports.SerialPort.GetPortNames();

            if(Comlist.Length<1) return ;

            comboBox1.Items.AddRange(Comlist) ;

            comboBox1.SelectedIndex=0 ;

            comboBox2.SelectedIndex=3 ;

            comboBox3.SelectedIndex=1 ;

            comboBox4.SelectedIndex=0 ;

            comboBox5.SelectedIndex=0 ;

        }

        private void button1_Click(object sender, EventArgs e)

        {

            if(serialPort.IsOpen) return ;

            try

            {

                serialPort.PortName = comboBox1.Text;

                serialPort.BaudRate = int.Parse(comboBox2.Text);

                serialPort.DataBits = int.Parse(comboBox3.Text);

                serialPort.Parity = (System.IO.Ports.Parity)Enum.Parse(typeof(System.IO.Ports.Parity), comboBox4.Text, true) ;

                serialPort.StopBits = (System.IO.Ports.StopBits)Enum.Parse(typeof(System.IO.Ports.StopBits), 

                          comboBox5.Text, true) ;

                serialPort.Open();

                serialPort.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(DataReceived) ;

                button1.BackColor = Color.LightGreen;

            }

            catch(Exception ex)

            {

                MessageBox.Show(ex.Message);

                button1.BackColor = Color.Pink;

            }

        }

        private void DataReceived(object sender, SerialDataReceivedEventArgs e)

        {

            const int MaxLen=10000;

            byte[] rByte = new byte[MaxLen];

            int len = serialPort.Read(rByte, 0, MaxLen);

            if(len<=0) return ;

            // Cross-thread operation not valid 

            // TextBox_Add(textBox1, Encoding.Default.GetString(rByte, 0, len));                        

            textBox_Invoke(textBox1, Encoding.Default.GetString(rByte, 0, len)) ;        // 받은 데이터는 가공없이 보여준다.

        }

        private void textBox_Invoke(TextBox tBox, string msg)

        {

            if(this.InvokeRequired)

            {

                this.Invoke(new MethodInvoker(delegate() {  TextBox_Add(tBox, msg) ;}));

            }

            else

                TextBox_Add(tBox, msg);

        }

        private void TextBox_Add(TextBox textBox, string str)

        {

            textBox.Text += str;        

            textBox.SelectixxxxxxxxonStart = textBox.Text.Length;

            textBox.ScrollToCaret();

        }

        private void textBox2_KeyPress(object sender, KeyPressEventArgs e)

        {

            if(!serialPort.IsOpen) return ;

            // Enter and Send Line

            if(e.KeyChar==(int)Keys.Enter)

            {

                int lines = textBox2.GetLineFromCharIndex(textBox2.SelectixxxxxxxxonStart);

                serialPort.Write(textBox2.Lines[lines] + "\r\n");

            }

            // Send input immediately

            //byte[] sendByte = Encoding.UTF8.GetBytes(e.KeyChar.ToString());

            //serialPort.Write(sendByte, 0, 1);

        }

    }

}