C# Console SerialReciving Monitor sendkey recieving

STA24_Console_MB_SerialMon_rev00.cs

using System;
using System.Collections.Generic;
using System.IO.Ports;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace STA24_Console_MB_SerialMon_rev00
{
    internal class Program
    {
        public static void serialOpen(string comst)
        {
          
            
        }
        static char key;
        static string comst="COM16";
        static void Main(string[] args)
        {
            Console.WriteLine("SerialPort default No="+comst+"(hit any key)  or Change (KeyIn  'c')");
            var inp = Console.ReadKey();//キーインしても表示しない  
            key = inp.KeyChar;
            if (key == 'c')
            {
                Console.Write("Input COM No=");
                comst = Console.ReadLine();
                //int comn = Convert.ToInt32(comst);
            }
            //
            SerialPort mySerialPort = new SerialPort(comst);
            mySerialPort.BaudRate = 115200;
            mySerialPort.Parity = Parity.None;
            mySerialPort.StopBits = StopBits.One;
            mySerialPort.DataBits = 8;
            mySerialPort.Handshake = Handshake.None;
            mySerialPort.RtsEnable = true;

            mySerialPort.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandler);

            mySerialPort.Open();

            Console.WriteLine("Key In a:start ");
            while (true)
            {
                key = ' ';
                 inp = Console.ReadKey();//キーインしても表示しない  
                key = inp.KeyChar;
                if (key != ' ' && key!='c')
                {
                    string skey = key.ToString();
                    mySerialPort.Write(skey);
                }
                
                
            }
            //Console.WriteLine("Press any key to continue...");
            //Console.WriteLine();
            //Console.ReadKey();
        

            //mySerialPort.Close();
            /*
            Console.WriteLine("Key In a start ");
            var inp = Console.ReadKey();//キーインしても表示しない
            key = inp.KeyChar;
            if (key == 'a')
              
            {
                //string dataToSend = "Hello Serial";
                //serialPort.Write(dataToSend);
                
             
                // データ受信
               
            }
            Console.ReadLine();
            */
        }
        private static void DataReceivedHandler(
                        object sender,
                        SerialDataReceivedEventArgs e)
        {
            SerialPort sp = (SerialPort)sender;
            string indata = sp.ReadExisting();
            //Console.WriteLine("Data Received:");
            Console.Write(indata);
        }
    }
}