C#, serialport_datareceived() event never fired for my mock interface

See more:

C#

serial-port

RS232

Hello all,

I am trying to create an application which will send a mock data on Serial Port COM1 for example a string "Hi".

Now this same application will try to read data from same COM1 i.e. I want to read same "hi" message from COM1. For this I have written the code but the serialPort_DataReceived() event never fire in my application. I don't know why i can get read the data from that port.

Is it not possible or something I am doing wrong?

What I have tried:

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;

namespace RS232MockInterface
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
            serialPort1.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(serialPort1_DataReceived);
            serialPort1.Open();
            serialPort1.Handshake = System.IO.Ports.Handshake.None;
            serialPort1.DtrEnable = true;
            serialPort1.RtsEnable = true;
            serialPort1.ReadTimeout = 6000;
            serialPort1.WriteTimeout = 6000;
        }

        delegate void OutputUpdateDelegate(string data);

        private void OutputUpdateCallback(string data)
        {
            txtMessages.Text += data;
            //MessageBox.Show(data);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if(!serialPort1.IsOpen)
            {
                serialPort1.Open();
                serialPort1.Handshake = System.IO.Ports.Handshake.None;
                serialPort1.DtrEnable = true;
                serialPort1.RtsEnable = true;
                serialPort1.ReadTimeout = 6000;
                serialPort1.WriteTimeout = 6000;
            }
            serialPort1.Write("Hi");
            string str = serialPort1.ReadExisting();
            //str = serialPort1.ReadLine();
        }

        private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
        {
            if (serialPort1.IsOpen)
            {
                String RecievedData;
                RecievedData = serialPort1.ReadExisting();
                if (!(RecievedData == ""))
                {
                    txtMessages.Invoke(new OutputUpdateDelegate(OutputUpdateCallback), RecievedData);
                }
              
            }
        }

        private void serialPort1_ErrorReceived(object sender, System.IO.Ports.SerialErrorReceivedEventArgs e)
        {

        }

        private void serialPort1_PinChanged(object sender, System.IO.Ports.SerialPinChangedEventArgs e)
        {

        }
    }
}