Modbus_Study/ModbusStudy/ModbusSlave/MainForm.cs

using EasyModbus;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Net.NetworkInformation;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace ModbusSlave
{
	public partial class MainForm : Form
	{
		public MainForm()
		{
			InitializeComponent();
			InitInstance();
		}

		#region Field

		private ModbusServer server;
		private bool isFirstLog = true;

		#endregion

		#region Button event

		private void btnRun_Click(object sender, EventArgs e)
		{
			try
			{
				server.Port = (int)nudPort.Value;
				server.UnitIdentifier = Convert.ToByte(nudAddress.Value);

				if (!CheckPortInUse(server.Port))
				{
					Log("[WARNING] unavailable port");
					return;
				}

				server.Listen();
				Log("--- Server start ---");

				btnRun.Enabled = false;
				nudAddress.Enabled = false;
				nudPort.Enabled = false;

				tbStatus.Text = "Run";
				tbStatus.BackColor = Color.Lime;
			}
			catch (Exception ex)
			{
				Log("[ERROR] " + ex.Message);
			}
		}

		private void btnStop_Click(object sender, EventArgs e)
		{
			try
			{
				server.StopListening();
				Log("--- Server stop ---");

				btnRun.Enabled = true;
				nudAddress.Enabled = true;
				nudPort.Enabled = true;

				tbStatus.Text = "Stop";
				tbStatus.BackColor = Color.Silver;
			}
			catch (Exception ex)
			{
				Log("[ERROR] " + ex.Message);
			}
		}

		private void btnClear_Click(object sender, EventArgs e)
		{
			ClearLog();
		}

		#endregion

		#region Timer event

		#endregion

		#region Listview event

		#endregion

		#region Etc event

		#endregion

		#region Method

		private void InitInstance()
		{
			server = new ModbusServer();
		}

		private void Log(string text)
		{
			rtbLog.AppendText((isFirstLog ? "" : Environment.NewLine) + text);
			isFirstLog = false;

			ScrollToEnd();
		}

		private void ScrollToEnd()
		{
			if (!chkAutoScroll.Checked)
				return;

			rtbLog.SelectionStart = rtbLog.Text.Length;
			rtbLog.ScrollToCaret();
		}

		private void ClearLog()
		{
			rtbLog.Clear();
			isFirstLog = true;
			ScrollToEnd();
		}

		private bool CheckPortInUse(int port)
		{
			bool isAvailable = true;
			var ipGlobalProperties = IPGlobalProperties.GetIPGlobalProperties();
			var tcpListenerArray = ipGlobalProperties.GetActiveTcpListeners();

			foreach (var ip in tcpListenerArray)
			{
				if (ip.Port == port)
				{
					isAvailable = false;
					break;
				}	
			}

			return isAvailable;
		}

		#endregion
	}
}