Connectivity Software User's Guide and Reference
Installed Examples - Server Windows Forms - UAServerWindowsFormsDemo
// A fully functional OPC UA demo server running in Windows Forms host.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System.Linq;
using System.Windows.Forms;
using Microsoft.Extensions.DependencyInjection;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Forms.Application;
using OpcLabs.EasyOpc.UA.OperationModel;
using OpcLabs.EasyOpc.UA.Services;
using UAServerDemoLibrary;

namespace UAServerWindowsFormsDemo
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();

            // Instantiating the EasyUAServer here, and not inline where the field is declared, is important for it to
            // acquire the proper synchronization context.
            _server = new EasyUAServer();
        }

        private void Form1_Load(object sender, System.EventArgs e)
        {
            // Extend the form's system menu by a command for OPC UA application management.
            EasyUAFormsApplication.Instance.AddToSystemMenu(this);

            // Define various nodes.
            DataNodes.AddToParent(_server.Objects);
            DemoNodes.AddToParent(_server.Objects);

            // Hook events to the server object.
            _server.EndpointStateChanged += ServerOnEndpointStateChanged;

            // Obtain the server connection monitoring service.
            IEasyUAServerConnectionMonitoring serverConnectionMonitoring = _server.GetService<IEasyUAServerConnectionMonitoring>();
            if (!(serverConnectionMonitoring is null))
            {
                // Hook events to the connection monitoring service.
                serverConnectionMonitoring.ClientSessionConnected += ServerConnectionMonitoringOnClientSessionConnected;
                serverConnectionMonitoring.ClientSessionDisconnected += ServerConnectionMonitoringOnClientSessionDisconnected;
            }

            _server.Start();
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            _server.Stop();
        }

        private void ServerOnEndpointStateChanged(object sender, EasyUAServerEndpointStateChangedEventArgs e)
        {
            // Note that since we have created the EasyUAServer on the UI thread, we can access the UI controls in its
            // event handlers directly, because the events are raised using the synchronization context acquired at time of
            // the creation.

            string endpointUrlString = e.EndpointUrlString;
            ListViewItem listViewItem = endpointStateListView.Items.Cast<ListViewItem>().FirstOrDefault(item => 
                item.Text == endpointUrlString);
            if (listViewItem is null)
            {
                listViewItem = new ListViewItem(endpointUrlString);
                endpointStateListView.Items.Add(listViewItem);
                listViewItem.SubItems.Add("");
                listViewItem.SubItems.Add("");
            }
            listViewItem.SubItems[1].Text = e.ConnectionState.ToString();
            listViewItem.SubItems[2].Text = e.Exception?.Message ?? "";
        }

        private void ServerConnectionMonitoringOnClientSessionConnected(object sender, EasyUAClientSessionConnectionEventArgs e)
        {
            // Note that since we have created the EasyUAServer on the UI thread, we can access the UI controls in its
            // event handlers directly, because the events are raised using the synchronization context acquired at time of
            // the creation.

            var listViewItem = new ListViewItem(e.SessionId.Identifier.ToString());
            listViewItem.SubItems.Add(e.SessionName);
            connectionsListView.Items.Add(listViewItem);
        }

        private void ServerConnectionMonitoringOnClientSessionDisconnected(object sender, EasyUAClientSessionConnectionEventArgs e)
        {
            // Note that since we have created the EasyUAServer on the UI thread, we can access the UI controls in its
            // event handlers directly, because the events are raised using the synchronization context acquired at time of
            // the creation.

            string identifierString = e.SessionId.Identifier.ToString();
            ListViewItem listViewItem = connectionsListView.Items.Cast<ListViewItem>().FirstOrDefault(item =>
                item.Text == identifierString);
            if (!(listViewItem is null))
                connectionsListView.Items.Remove(listViewItem);
        }

        private readonly EasyUAServer _server;
    }
}
' A fully functional OPC UA demo server running in Windows Forms host.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports System.Linq
Imports System.Windows.Forms
Imports Microsoft.Extensions.DependencyInjection
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.Forms.Application
Imports OpcLabs.EasyOpc.UA.OperationModel
Imports OpcLabs.EasyOpc.UA.Services
Imports UAServerDemoLibrary

Public Class MainForm
    Sub New()
        InitializeComponent()

        ' Instantiating the EasyUAServer here, and not inline where the field is declared, is important for it to
        ' acquire the proper synchronization context.
        _server = New EasyUAServer()
    End Sub

    Private Sub MainForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' Extend the form's system menu by a command for OPC UA application management.
        EasyUAFormsApplication.Instance.AddToSystemMenu(Me)

        ' Define various nodes.
        DataNodes.AddToParent(_server.Objects)
        DemoNodes.AddToParent(_server.Objects)

        ' Hook events to the server object.
        AddHandler _server.EndpointStateChanged, AddressOf ServerOnEndpointStateChanged

        ' Obtain the server connection monitoring service.
        Dim serverConnectionMonitoring As IEasyUAServerConnectionMonitoring = _server.GetService(Of IEasyUAServerConnectionMonitoring)()
        If (Not (serverConnectionMonitoring Is Nothing)) Then
            ' Hook events to the connection monitoring service.
            AddHandler serverConnectionMonitoring.ClientSessionConnected, AddressOf ServerConnectionMonitoringOnClientSessionConnected
            AddHandler serverConnectionMonitoring.ClientSessionDisconnected, AddressOf ServerConnectionMonitoringOnClientSessionDisconnected
        End If

        _server.Start()
    End Sub

    Private ReadOnly _server As EasyUAServer

    Private Sub MainForm_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
        _server.Stop()
    End Sub

    Private Sub ServerOnEndpointStateChanged(sender As Object, e As EasyUAServerEndpointStateChangedEventArgs)
        ' Note that since we have created the EasyUAServer on the UI thread, we can access the UI controls in its
        ' event handlers directly, because the events are raised using the synchronization context acquired at time of
        ' the creation.

        Dim endpointUrlString As String = e.EndpointUrlString
        Dim listViewItem As ListViewItem = endpointStateListView.Items.Cast(Of ListViewItem)().FirstOrDefault(Function(item) _
            item.Text = endpointUrlString)
        If (listViewItem Is Nothing) Then
            listViewItem = New ListViewItem(endpointUrlString)
            endpointStateListView.Items.Add(listViewItem)
            listViewItem.SubItems.Add("")
            listViewItem.SubItems.Add("")
        End If
        listViewItem.SubItems(1).Text = e.ConnectionState.ToString()
        listViewItem.SubItems(2).Text = If(e.Exception?.Message, "")
    End Sub

    Private Sub ServerConnectionMonitoringOnClientSessionConnected(sender As Object, e As EasyUAClientSessionConnectionEventArgs)
        ' Note that since we have created the EasyUAServer on the UI thread, we can access the UI controls in its
        ' event handlers directly, because the events are raised using the synchronization context acquired at time of
        ' the creation.

        Dim listViewItem = New ListViewItem(e.SessionId.Identifier.ToString())
        listViewItem.SubItems.Add(e.SessionName)
        connectionsListView.Items.Add(listViewItem)
    End Sub

    Private Sub ServerConnectionMonitoringOnClientSessionDisconnected(sender As Object, e As EasyUAClientSessionConnectionEventArgs)
        ' Note that since we have created the EasyUAServer on the UI thread, we can access the UI controls in its
        ' event handlers directly, because the events are raised using the synchronization context acquired at time of
        ' the creation.

        Dim identifierString As String = e.SessionId.Identifier.ToString()
        Dim listViewItem As ListViewItem = connectionsListView.Items.Cast(Of ListViewItem)().FirstOrDefault(Function(item) _
        item.Text = identifierString)
        If (Not (listViewItem Is Nothing)) Then
            connectionsListView.Items.Remove(listViewItem)
        End If
    End Sub

End Class
// A fully functional OPC UA demo server running in Windows Forms host.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

namespace UAServerWindowsFormsDemo
{
    partial class MainForm
    {
        /// <summary>
        ///  Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        ///  Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        ///  Required method for Designer support - do not modify
        ///  the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.label1 = new System.Windows.Forms.Label();
            this.endpointStateListView = new System.Windows.Forms.ListView();
            this.columnHeader1 = ((System.Windows.Forms.ColumnHeader)(new System.Windows.Forms.ColumnHeader()));
            this.columnHeader2 = ((System.Windows.Forms.ColumnHeader)(new System.Windows.Forms.ColumnHeader()));
            this.columnHeader3 = ((System.Windows.Forms.ColumnHeader)(new System.Windows.Forms.ColumnHeader()));
            this.label2 = new System.Windows.Forms.Label();
            this.connectionsListView = new System.Windows.Forms.ListView();
            this.columnHeader4 = ((System.Windows.Forms.ColumnHeader)(new System.Windows.Forms.ColumnHeader()));
            this.columnHeader5 = ((System.Windows.Forms.ColumnHeader)(new System.Windows.Forms.ColumnHeader()));
            this.SuspendLayout();
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.Location = new System.Drawing.Point(13, 13);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(83, 13);
            this.label1.TabIndex = 0;
            this.label1.Text = "Endpoint states:";
            // 
            // endpointStateListView
            // 
            this.endpointStateListView.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) 
            | System.Windows.Forms.AnchorStyles.Right)));
            this.endpointStateListView.Columns.AddRange(new System.Windows.Forms.ColumnHeader[] {
            this.columnHeader1,
            this.columnHeader2,
            this.columnHeader3});
            this.endpointStateListView.FullRowSelect = true;
            this.endpointStateListView.HideSelection = false;
            this.endpointStateListView.Location = new System.Drawing.Point(13, 30);
            this.endpointStateListView.Name = "endpointStateListView";
            this.endpointStateListView.Size = new System.Drawing.Size(775, 97);
            this.endpointStateListView.TabIndex = 1;
            this.endpointStateListView.UseCompatibleStateImageBehavior = false;
            this.endpointStateListView.View = System.Windows.Forms.View.Details;
            // 
            // columnHeader1
            // 
            this.columnHeader1.Text = "Endpoint URL";
            this.columnHeader1.Width = 240;
            // 
            // columnHeader2
            // 
            this.columnHeader2.Text = "State";
            this.columnHeader2.Width = 80;
            // 
            // columnHeader3
            // 
            this.columnHeader3.Text = "Message";
            this.columnHeader3.Width = 440;
            // 
            // label2
            // 
            this.label2.AutoSize = true;
            this.label2.Location = new System.Drawing.Point(13, 134);
            this.label2.Name = "label2";
            this.label2.Size = new System.Drawing.Size(69, 13);
            this.label2.TabIndex = 2;
            this.label2.Text = "Connections:";
            // 
            // connectionsListView
            // 
            this.connectionsListView.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom) 
            | System.Windows.Forms.AnchorStyles.Left) 
            | System.Windows.Forms.AnchorStyles.Right)));
            this.connectionsListView.Columns.AddRange(new System.Windows.Forms.ColumnHeader[] {
            this.columnHeader4,
            this.columnHeader5});
            this.connectionsListView.FullRowSelect = true;
            this.connectionsListView.HideSelection = false;
            this.connectionsListView.Location = new System.Drawing.Point(13, 151);
            this.connectionsListView.Name = "connectionsListView";
            this.connectionsListView.Size = new System.Drawing.Size(775, 287);
            this.connectionsListView.TabIndex = 3;
            this.connectionsListView.UseCompatibleStateImageBehavior = false;
            this.connectionsListView.View = System.Windows.Forms.View.Details;
            // 
            // columnHeader4
            // 
            this.columnHeader4.Text = "Identifier";
            this.columnHeader4.Width = 80;
            // 
            // columnHeader5
            // 
            this.columnHeader5.Text = "Session Name";
            this.columnHeader5.Width = 480;
            // 
            // Form1
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(800, 450);
            this.Controls.Add(this.connectionsListView);
            this.Controls.Add(this.label2);
            this.Controls.Add(this.endpointStateListView);
            this.Controls.Add(this.label1);
            this.Name = "MainForm";
            this.Text = "OPC Wizard Server Windows Forms Demo";
            this.FormClosing += new System.Windows.Forms.FormClosingEventHandler(this.Form1_FormClosing);
            this.Load += new System.EventHandler(this.Form1_Load);
            this.ResumeLayout(false);
            this.PerformLayout();

        }
' A fully functional OPC UA demo server running in Windows Forms host.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()>
Partial Class MainForm
    Inherits System.Windows.Forms.Form

    'Form overrides dispose to clean up the component list.
    <System.Diagnostics.DebuggerNonUserCode()>
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        Try
            If disposing AndAlso components IsNot Nothing Then
                components.Dispose()
            End If
        Finally
            MyBase.Dispose(disposing)
        End Try
    End Sub

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()>
    Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label()
        Me.endpointStateListView = New System.Windows.Forms.ListView()
        Me.ColumnHeader1 = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
        Me.ColumnHeader2 = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
        Me.ColumnHeader3 = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
        Me.Label2 = New System.Windows.Forms.Label()
        Me.connectionsListView = New System.Windows.Forms.ListView()
        Me.ColumnHeader4 = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
        Me.ColumnHeader5 = CType(New System.Windows.Forms.ColumnHeader(), System.Windows.Forms.ColumnHeader)
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.AutoSize = True
        Me.Label1.Location = New System.Drawing.Point(13, 13)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(83, 13)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "Endpoint states:"
        '
        'endpointStateListView
        '
        Me.endpointStateListView.Anchor = CType(((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Left) _
            Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)
        Me.endpointStateListView.Columns.AddRange(New System.Windows.Forms.ColumnHeader() {Me.ColumnHeader1, Me.ColumnHeader2, Me.ColumnHeader3})
        Me.endpointStateListView.HideSelection = False
        Me.endpointStateListView.Location = New System.Drawing.Point(13, 30)
        Me.endpointStateListView.Name = "endpointStateListView"
        Me.endpointStateListView.Size = New System.Drawing.Size(775, 97)
        Me.endpointStateListView.TabIndex = 1
        Me.endpointStateListView.UseCompatibleStateImageBehavior = False
        Me.endpointStateListView.View = System.Windows.Forms.View.Details
        '
        'ColumnHeader1
        '
        Me.ColumnHeader1.Text = "Endpoint URL"
        Me.ColumnHeader1.Width = 240
        '
        'ColumnHeader2
        '
        Me.ColumnHeader2.Text = "State"
        Me.ColumnHeader2.Width = 80
        '
        'ColumnHeader3
        '
        Me.ColumnHeader3.Text = "Message"
        Me.ColumnHeader3.Width = 440
        '
        'Label2
        '
        Me.Label2.AutoSize = True
        Me.Label2.Location = New System.Drawing.Point(13, 134)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(69, 13)
        Me.Label2.TabIndex = 2
        Me.Label2.Text = "Connections:"
        '
        'connectionsListView
        '
        Me.connectionsListView.Anchor = CType((((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _
            Or System.Windows.Forms.AnchorStyles.Left) _
            Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)
        Me.connectionsListView.Columns.AddRange(New System.Windows.Forms.ColumnHeader() {Me.ColumnHeader4, Me.ColumnHeader5})
        Me.connectionsListView.FullRowSelect = True
        Me.connectionsListView.Location = New System.Drawing.Point(13, 151)
        Me.connectionsListView.Name = "connectionsListView"
        Me.connectionsListView.Size = New System.Drawing.Size(775, 287)
        Me.connectionsListView.TabIndex = 3
        Me.connectionsListView.UseCompatibleStateImageBehavior = False
        Me.connectionsListView.View = System.Windows.Forms.View.Details
        '
        'ColumnHeader4
        '
        Me.ColumnHeader4.Text = "Identifier"
        Me.ColumnHeader4.Width = 80
        '
        'ColumnHeader5
        '
        Me.ColumnHeader5.Text = "Session Name"
        Me.ColumnHeader5.Width = 480
        '
        'MainForm
        '
        Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
        Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
        Me.ClientSize = New System.Drawing.Size(800, 450)
        Me.Controls.Add(Me.connectionsListView)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.endpointStateListView)
        Me.Controls.Add(Me.Label1)
        Me.Name = "MainForm"
        Me.Text = "OPC Wizard Server Windows Forms Demo"
        Me.ResumeLayout(False)
        Me.PerformLayout()

    End Sub

    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents endpointStateListView As System.Windows.Forms.ListView
    Friend WithEvents ColumnHeader1 As System.Windows.Forms.ColumnHeader
    Friend WithEvents ColumnHeader2 As System.Windows.Forms.ColumnHeader
    Friend WithEvents ColumnHeader3 As System.Windows.Forms.ColumnHeader
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents connectionsListView As System.Windows.Forms.ListView
    Friend WithEvents ColumnHeader4 As System.Windows.Forms.ColumnHeader
    Friend WithEvents ColumnHeader5 As System.Windows.Forms.ColumnHeader
End Class
// A fully functional OPC UA demo server running in Windows Forms host.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// OPC client, server and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using System.Windows.Forms;
using Opc.Ua;
using OpcLabs.EasyOpc.UA;

namespace UAServerWindowsFormsDemo
{
    internal static class Program
    {
        /// <summary>
        ///  The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
#if (NET6_0_OR_GREATER)
            // To customize application configuration such as set high DPI settings or default font,
            // see https://aka.ms/applicationconfiguration.
            ApplicationConfiguration.Initialize();
#endif

            // Enable the Windows Forms interaction by the server.
            EasyUAServer.SharedParameters.PluginSetups.FindName("UAWindowsFormsInteraction").Enabled = true;

            Application.Run(new MainForm());
        }
    }
}
' A fully functional OPC UA demo server running in Windows Forms host.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-ConnectivityStudio-VBNET .
' Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
' a commercial license in order to use Online Forums, and we reply to every post.

Imports System
Imports System.Windows.Forms
Imports OpcLabs.EasyOpc.UA

Namespace UAServerWindowsFormsDemo
    Module Program
        Sub Main(args As String())
#If (NET6_0_OR_GREATER) Then
            ' To customize application configuration such as set high DPI settings or default font,
            ' see https://aka.ms/applicationconfiguration.
            'ApplicationConfiguration.Initialize()
#End If

            ' Enable the Windows Forms interaction by the server.
            EasyUAServer.SharedParameters.PluginSetups.FindName("UAWindowsFormsInteraction").Enabled = True

            Application.Run(New MainForm())
        End Sub
    End Module
End Namespace
See Also

Installed Examples - Server Console

Installed Examples - Server Library

Installed Examples - Server Windows Service

Installed Examples - Server Worker Service

Examples - Server OPC Unified Architecture