Installed Examples - WindowsForms

This is a source of the Windows Forms Demo application for OPC-UA that ships with OPC Data Client. The application shows the most important product functions, including event-based subscriptions.

The main form:

C#
VB.NET

// $Header: $ 
// Copyright (c) CODE Consulting and Development, s.r.o., Plzen. All rights reserved.

//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

using System;
using System.Globalization;
using System.Reflection;
using System.Windows.Forms;
using EasyOpcUADemo.Properties;
using JetBrains.Annotations;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.Forms.Application;
using OpcLabs.EasyOpc.UA.OperationModel;

// ReSharper disable AssignNullToNotNullAttribute
// ReSharper disable InconsistentNaming
// ReSharper disable NotNullMemberIsNotInitialized
// ReSharper disable PossibleNullReferenceException

[assembly:CLSCompliant(true)]
namespace EasyOpcUADemo
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void readButton_Click(object sender, EventArgs e)
        {
            UAAttributeData attributeData = null;
            Exception exception = null;
            try
            {
                attributeData = easyUAClient1.Read(serverUriTextBox.Text, nodeIdTextBox.Text);
            }
            catch (UAException ex)
            {
                exception = ex;
            }
            DisplayAttributeData(attributeData);
            DisplayException(exception);
        }

        private void DisplayAttributeData(UAAttributeData attributeData)
        {
            if (attributeData is null)
            {
                valueTextBox.Text = "";
                statusTextBox.Text = "";
                sourceTimestampTextBox.Text = "";
                serverTimestampTextBox.Text = "";
            }
            else
            {
                valueTextBox.Text = attributeData.DisplayValue();
                statusTextBox.Text = attributeData.StatusCode.ToString();
                sourceTimestampTextBox.Text = attributeData.SourceTimestamp.ToString(CultureInfo.CurrentCulture);
                serverTimestampTextBox.Text = attributeData.ServerTimestamp.ToString(CultureInfo.CurrentCulture);
            }
        }

        private void DisplayException(Exception exception)
        {
            exceptionTextBox.Text = (exception is null) ? "" : exception.GetBaseException().Message;
        }

        private bool _isSubscribed/* = false*/;
        private int _handle/* = 0*/;

        public bool IsSubscribed
        {
            get { return _isSubscribed; }
            set 
            {
                _isSubscribed = value;
                subscribeMonitoredItemButton.Enabled = !_isSubscribed;
                changeMonitoredItemSubscriptionButton.Enabled = _isSubscribed;
                unsubscribeMonitoredItemButton.Enabled = _isSubscribed;
            }
        }

        private void subscribeButton_Click(object sender, EventArgs e)
        {
            _handle = easyUAClient1.SubscribeDataChange(serverUriTextBox.Text, nodeIdTextBox.Text,
                                                           (int)samplingIntervalNumericUpDown.Value);
            IsSubscribed = true;
        }

        private void changeSubscriptionButton_Click(object sender, EventArgs e)
        {
            easyUAClient1.ChangeMonitoredItemSubscription(_handle, (int)samplingIntervalNumericUpDown.Value);
        }

        private void unsubscribeButton_Click(object sender, EventArgs e)
        {
            Unsubscribe();
        }

        private void Unsubscribe()
        {
            easyUAClient1.UnsubscribeMonitoredItem(_handle);
            _handle = 0;
            IsSubscribed = false;
        }

        private void easyUAClient1_DataChangeNotification(object sender, EasyUADataChangeNotificationEventArgs e)
        {
            DisplayAttributeData((e.Exception is null) ? e.AttributeData : null);
            DisplayException(e.Exception);
        }

        private void aboutButton_Click(object sender, EventArgs e)
        {
            MessageBox.Show(this, Assembly.GetExecutingAssembly().FullName, Resources.MainForm_AssemblyName, 
                MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        private void closeButton_Click(object sender, EventArgs e)
        {
            if (IsSubscribed)
                Unsubscribe();
            Close();
        }

        private void MainForm_Load(object sender, EventArgs e)
        {
            EasyUAFormsApplication.Instance.AddToSystemMenu(this);
        }

        private void discoverServersButton_Click(object sender, EventArgs e)
        {
            uaHostAndEndpointDialog1.EndpointDescriptor = serverUriTextBox.Text;
            if (uaHostAndEndpointDialog1.ShowDialog() == DialogResult.OK)
                serverUriTextBox.Text = uaHostAndEndpointDialog1.EndpointDescriptor.UrlString;
        }

        private void browseDataButton_Click(object sender, EventArgs e)
        {
            uaDataDialog1.EndpointDescriptor = serverUriTextBox.Text;
            if (uaDataDialog1.ShowDialog() == DialogResult.OK)
                nodeIdTextBox.Text = uaDataDialog1.NodeDescriptor.NodeId;
        }

        private void writeValueButton_Click(object sender, EventArgs e)
        {
            Exception exception = null;
            try
            {
                easyUAClient1.WriteValue(serverUriTextBox.Text, nodeIdTextBox.Text, valueToWriteTextBox.Text);
            }
            catch (UAException ex)
            {
                exception = ex;
            }
            DisplayException(exception);
        }
    }
}

' $Header: $ 
' Copyright (c) CODE Consulting and Development, s.r.o., Plzen. All rights reserved.

'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .

Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.Forms.Application
Imports OpcLabs.EasyOpc.UA.OperationModel

<Assembly: CLSCompliant(True)>

Partial Public Class MainForm
    Inherits Form
    Public Sub New()
        InitializeComponent()
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub readButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles readButton.Click
        ' ReSharper restore InconsistentNaming

        Dim attributeData As UAAttributeData = Nothing
        Dim exception As Exception = Nothing
        Try
            attributeData = easyUAClient1.Read(serverUriTextBox.Text, nodeIdTextBox.Text)
        Catch ex As UAException
            exception = ex
        End Try
        DisplayAttributeData(attributeData)
        DisplayException(exception)
    End Sub

    Private Sub DisplayAttributeData(ByVal attributeData As UAAttributeData)
        If attributeData Is Nothing Then
            valueTextBox.Text = ""
            statusTextBox.Text = ""
            sourceTimestampTextBox.Text = ""
            serverTimestampTextBox.Text = ""
        Else
            valueTextBox.Text = attributeData.DisplayValue()
            statusTextBox.Text = attributeData.StatusCode.ToString()
            sourceTimestampTextBox.Text = attributeData.SourceTimestamp.ToString()
            serverTimestampTextBox.Text = attributeData.ServerTimestamp.ToString()
        End If
    End Sub

    Private Sub DisplayException(ByVal exception As Exception)
        exceptionTextBox.Text = If(exception Is Nothing, "", exception.GetBaseException().Message)
    End Sub

    Private _isSubscribed As Boolean ' = false
    Private _handle As Integer ' = 0

    Public Property IsSubscribed() As Boolean
        Get
            Return _isSubscribed
        End Get
        Set(ByVal value As Boolean)
            _isSubscribed = value
            subscribeMonitoredItemButton.Enabled = Not _isSubscribed
            changeMonitoredItemSubscriptionButton.Enabled = _isSubscribed
            unsubscribeMonitoredItemButton.Enabled = _isSubscribed
        End Set
    End Property

    ' ReSharper disable InconsistentNaming
    Private Sub subscribeButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles subscribeMonitoredItemButton.Click
        ' ReSharper restore InconsistentNaming

        _handle = easyUAClient1.SubscribeDataChange(serverUriTextBox.Text, nodeIdTextBox.Text, CInt(Fix(samplingIntervalNumericUpDown.Value)))
        IsSubscribed = True
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub changeSubscriptionButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles changeMonitoredItemSubscriptionButton.Click
        ' ReSharper restore InconsistentNaming
        easyUAClient1.ChangeMonitoredItemSubscription(_handle, CInt(Fix(samplingIntervalNumericUpDown.Value)))
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub unsubscribeButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles unsubscribeMonitoredItemButton.Click
        ' ReSharper restore InconsistentNaming
        Unsubscribe()
    End Sub

    Private Sub Unsubscribe()
        easyUAClient1.UnsubscribeMonitoredItem(_handle)
        _handle = 0
        IsSubscribed = False
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub easyUAClient1_DataChangeNotification(ByVal sender As Object, ByVal e As EasyUADataChangeNotificationEventArgs) Handles easyUAClient1.DataChangeNotification
        ' ReSharper restore InconsistentNaming
        DisplayAttributeData(If(e.Exception Is Nothing, e.AttributeData, Nothing))
        DisplayException(e.Exception)
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub aboutButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles aboutButton.Click
        ' ReSharper restore InconsistentNaming
        MessageBox.Show(Me, Reflection.Assembly.GetExecutingAssembly().FullName, My.Resources.MainForm_AssemblyName, MessageBoxButtons.OK, MessageBoxIcon.Information)
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub closeButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles closeButton.Click
        ' ReSharper restore InconsistentNaming
        If IsSubscribed Then
            Unsubscribe()
        End If
        Close()
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub MainForm_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        ' ReSharper restore InconsistentNaming
        EasyUAFormsApplication.Instance.AddToSystemMenu(Me)
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub writeValueButton_Click(ByVal sender As System.Object, ByVal e As EventArgs) Handles writeValueButton.Click
        ' ReSharper restore InconsistentNaming

        Dim exception As Exception = Nothing
        Try
            easyUAClient1.WriteValue(serverUriTextBox.Text, nodeIdTextBox.Text, valueToWriteTextBox.Text)
        Catch ex As UAException
            exception = ex
        End Try
        DisplayException(exception)
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub discoverServersButton_Click(ByVal sender As System.Object, ByVal e As EventArgs) Handles discoverServersButton.Click
        ' ReSharper restore InconsistentNaming

        uaHostAndEndpointDialog1.EndpointDescriptor = serverUriTextBox.Text
        If uaHostAndEndpointDialog1.ShowDialog() = DialogResult.OK Then
            serverUriTextBox.Text = uaHostAndEndpointDialog1.EndpointDescriptor.UrlString
        End If
    End Sub

    ' ReSharper disable InconsistentNaming
    Private Sub browseDataButton_Click(ByVal sender As System.Object, ByVal e As EventArgs) Handles browseDataButton.Click
        ' ReSharper restore InconsistentNaming

        uaDataDialog1.EndpointDescriptor = serverUriTextBox.Text
        If uaDataDialog1.ShowDialog() = DialogResult.OK Then
            nodeIdTextBox.Text = uaDataDialog1.NodeDescriptor.NodeId
        End If
    End Sub
End Class

Conceptual

Examples for OPC Unified Architecture (OPC-UA)

Imperative Programming Model for OPC Data (Classic and UA)

.NET Framework Demo Applications for OPC UA (Client-Server)

Installed Examples - WPF

Installed Examples - WPF - WpfEasyOpcUADemo