C# Serial Recive Send Test

Serial_Test_rev01.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO.Ports;
using System.Diagnostics;
using static System.Net.Mime.MediaTypeNames;
using static System.Windows.Forms.VisualStyles.VisualStyleElement;

namespace SerialTest_rev01
{
    public partial class Form1 : Form
    {
        int i;
       public struct rdata
        {
            public string[] lines;
            public string[] sline;
            public string itowB;
        }
        rdata r;
        public Form1()
        {
            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)
        {
            serialPort1.BaudRate = 115200;
            serialPort1.Parity = Parity.None;
            serialPort1.DataBits = 8;
            serialPort1.StopBits = StopBits.One;
            serialPort1.Handshake = Handshake.None;
            serialPort1.PortName = portComboBox.Text;
            serialPort1.Open();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string[] ports = SerialPort.GetPortNames();
            foreach (string port in ports)
            {
                portComboBox.Items.Add(port);
            }
            if (portComboBox.Items.Count > 0)
                portComboBox.SelectedIndex = 0;
        }

        

        delegate void DataDelegate(string sdata);
        //=================printdata 内でデータ処理================================
        private void printdata(string text)
        {
            textBox1.AppendText(text);
            richTextBox1.AppendText(text);
            richTextBox1.ScrollToCaret();
            /*
            r.lines = text.Split('[');
            r.sline = r.lines[1].Split(',');
            for(i=0;i<r.sline.Length-1;i++)
            {
                Debug.Print("sline[" + i.ToString() + "]=" + r.sline[i].ToString());
            }
            */
        }
        
    // -------------------Serial受信部--------------------------------------------------
      private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            string str = serialPort1.ReadLine();
            DataDelegate a = new DataDelegate(printdata);
            BeginInvoke(a, str);
        }
    //-----------------------------------------------------------------------------------
        private void button2_Click(object sender, EventArgs e)
        {

        }

        private void button3_Click(object sender, EventArgs e)
        {
            serialPort1.Close();
        }

        private void button4_Click(object sender, EventArgs e)
        {
            if (serialPort1.IsOpen)
            {
                serialPort1.Write("p");
            }
        }

        private void button5_Click(object sender, EventArgs e)
        {
            if (serialPort1.IsOpen)
            {
                serialPort1.Write("d");
            }
        }

        private void button6_Click(object sender, EventArgs e)
        {
            if (serialPort1.IsOpen)
            {
                serialPort1.Write("a");
            }
        }

        private void button2_Click_1(object sender, EventArgs e)
        {
            if (serialPort1.IsOpen)
            {
                serialPort1.Write("s");
            }
        }
    }
}