SerialPort.DataReceived isn't firing for Windows App , Working fine in Console App .net2.0 [closed]

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Closed 8 years ago.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;

using System.Text;
using System.Windows.Forms;
using System.IO.Ports;

namespace ReadWieght
{
    public partial class Form1 : Form
    {
        public delegate void UpdateTextCallback(string text);

        private void Form1_Load(object sender, EventArgs e)
        {
            ReadSP();
        }
        void ReadSP()
        {

            SerialPort mySerialPort = null;
            mySerialPort = new SerialPort("COM1");
            mySerialPort.BaudRate = 2400;
            mySerialPort.Parity = Parity.None;
            mySerialPort.StopBits = StopBits.One;
            mySerialPort.DataBits = 8;
            mySerialPort.Handshake = Handshake.RequestToSend;
            mySerialPort.DtrEnable = true;
            mySerialPort.RtsEnable = true; 

            mySerialPort.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived);
            try
            {
                mySerialPort.Open();
                // mySerialPort.Write(str.Trim()); 
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

            mySerialPort.Close();
        }

        // Updates the textbox text.
        private void UpdateText(string text)
        {
            // Set the textbox text.
            label1.Text = text;
        }


        //static string text = null;
        private  void port_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            this.Invoke(new UpdateTextCallback(this.UpdateText), new object[] { "DATA RECIEVED" });


            try
            {
                SerialPort sp = (SerialPort)sender;
                byte[] comBuffer = new byte[sp.BytesToRead];
                sp.Read(comBuffer, 0, sp.BytesToRead);
                Console.WriteLine(Encoding.ASCII.GetString(comBuffer));
                // char[] chr = Encoding.ASCII.GetString(comBuffer);
                string str = Encoding.ASCII.GetString(comBuffer);
                if (str.Length > 7)
                {
                    str = str.Substring(2, 6);

                    this.Invoke((MethodInvoker)delegate
                    {
                        label1.Text = str; // runs on UI thread
                    }); 
                }
                Encoding.ASCII.GetString(comBuffer);

            }
            catch (Exception ex)
            {
               // MessageBox.Show(ex.Message);
                this.Invoke((MethodInvoker)delegate
                {
                    label1.Text = ex.Message; // runs on UI thread
                }); 
            }

        }

        public Form1()
        {
            InitializeComponent();
        }






}
}

Answer 1

Put the mySerialPort variable outside of the ReadSP function otherwise it's going to be destroyed when that function finishes. Close the port in another function.

Answer 2

You've commented out the line that writes to the serial port, so it looks to me like you're not sending any data down the serial port so maybe that's why a request isn't being received?

For testing I'd recommend a "loop back" which is basically linking the rx & tx lines on your serial port. You can use a metal paper clip for this - just stick each end in pins 2 & 3.