NodeElement Property (UABrowseNodeElement)

Gets the information about the OPC-UA node selected in the dialog box.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Public Property NodeElement As UANodeElement

'Usage
 
Dim instance As UABrowseNodeElement
Dim value As UANodeElement
 
instance.NodeElement = value
 
value = instance.NodeElement

public UANodeElement NodeElement {get; set;}

public:
property UANodeElement^ NodeElement {
   UANodeElement^ get();
   void set (    UANodeElement^ value);
}

Property Value

This value of this property can be null (Nothing in Visual Basic).

The default value of this property is null.

Because the OpcLabs.EasyOpc.UA.UANodeDescriptor has an implicit conversion from OpcLabs.EasyOpc.UA.AddressSpace.UANodeElement, you can simply use the returned OpcLabs.EasyOpc.UA.AddressSpace.UANodeElement in any place where OpcLabs.EasyOpc.UA.UANodeDescriptor is expected as input, and the corresponding node descriptor will be constructed automatically from the node element. When the implicit conversion operators are not supported (such as with Python.NET), you can use the OpcLabs.EasyOpc.UA.AddressSpace.UANodeElement.ToUANodeDescriptor static method instead.

Remarks

The getter method of this property is pure, i.e. it does not have observable side effects.

Example

CSharp
VB.NET

// This example shows how to allow browsing for an OPC Unified Architecture node by placing a browsing control on the form.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-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 OpcLabs.BaseLib;
using OpcLabs.EasyOpc.UA.Forms.Browsing;

namespace UAFormsDocExamples._UABrowseControl
{
    public partial class UsageForm : Form
    {
        public UsageForm()
        {
            InitializeComponent();
        }

        private void getOutputsButton_Click(object sender, EventArgs e)
        {
            // Obtain the current node element.
            UABrowseNodeElement currentNodeElement = uaBrowseControl1.Outputs.CurrentNodeElement;

            // Display the present parts of the current node element in the outputs text text box.
            outputsTextBox.Text = "";
            if (!(currentNodeElement.HostElement is null))
                outputsTextBox.Text += $"{nameof(UABrowseNodeElement.HostElement)}: {currentNodeElement.HostElement}\r\n";
            if (!(currentNodeElement.DiscoveryElement is null))
                outputsTextBox.Text += $"{nameof(UABrowseNodeElement.DiscoveryElement)}: {currentNodeElement.DiscoveryElement}\r\n";
            if (!(currentNodeElement.NodeElement is null))
                outputsTextBox.Text += $"{nameof(UABrowseNodeElement.NodeElement)}: {currentNodeElement.NodeElement}\r\n";
        }

        private void uaBrowseControl1_BrowseFailure(object sender, FailureEventArgs e)
        {
            // Append the event name and its arguments to the browsing events text box.
            browsingEventsTextBox.Text += $"{nameof(UABrowseControl.BrowseFailure)}: {e}\r\n";
        }

        private void uaBrowseControl1_CurrentNodeChanged(object sender, EventArgs e)
        {
            // Append the event name and the current node element to the browsing events text box.
            browsingEventsTextBox.Text += $"{nameof(UABrowseControl.CurrentNodeChanged)}; {uaBrowseControl1.Outputs.CurrentNodeElement}\r\n";
        }

        private void uaBrowseControl1_NodeDoubleClick(object sender, EventArgs e)
        {
            // Append the event name to the browsing events text box.
            browsingEventsTextBox.Text += $"{nameof(UABrowseControl.NodeDoubleClick)}\r\n";
        }

        private void uaBrowseControl1_SelectionChanged(object sender, EventArgs e)
        {
            // Append the event name to the browsing events text box.
            browsingEventsTextBox.Text += $"{nameof(UABrowseControl.SelectionChanged)}\r\n";
        }

        private void setInputsButton_Click(object sender, EventArgs e)
        {
            // Set the current node to our pre-defined OPC UA server.
            uaBrowseControl1.InputsOutputs.CurrentNodeDescriptor.EndpointDescriptor = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer";
        }
    }
}

' This example shows how to allow browsing for an OPC Unified Architecture node by placing a browsing control on the form.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
' OPC client and subscriber examples in VB.NET on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-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 OpcLabs.EasyOpc.UA.Forms.Browsing
Imports OpcLabs.BaseLib

Namespace UAFormsDocExamples._UABrowseControl
    Public Class UsageForm
        Private Sub getOutputsButton_Click(sender As Object, e As EventArgs) Handles getOutputsButton.Click
            ' Obtain the current node element.
            Dim currentNodeElement As UABrowseNodeElement = uaBrowseControl1.Outputs.CurrentNodeElement

            ' Display the present parts of the current node element in the outputs text text box.
            outputsTextBox.Text = ""
            If currentNodeElement.HostElement IsNot Nothing Then
                outputsTextBox.Text += $"{NameOf(UABrowseNodeElement.HostElement)}: {currentNodeElement.HostElement}" + Environment.NewLine
            End If
            If currentNodeElement.DiscoveryElement IsNot Nothing Then
                outputsTextBox.Text += $"{NameOf(UABrowseNodeElement.DiscoveryElement)}: {currentNodeElement.DiscoveryElement}" + Environment.NewLine
            End If
            If currentNodeElement.NodeElement IsNot Nothing Then
                outputsTextBox.Text += $"{NameOf(UABrowseNodeElement.NodeElement)}: {currentNodeElement.NodeElement}" + Environment.NewLine
            End If
        End Sub

        Private Sub uaBrowseControl1_BrowseFailure(sender As Object, e As FailureEventArgs) Handles uaBrowseControl1.BrowseFailure
            ' Append the event name and its arguments to the browsing events text box.
            browsingEventsTextBox.Text += $"{NameOf(UABrowseControl.BrowseFailure)}: {e}" + Environment.NewLine
        End Sub

        Private Sub uaBrowseControl1_CurrentNodeChanged(sender As Object, e As EventArgs) Handles uaBrowseControl1.CurrentNodeChanged
            ' Append the event name and the current node element to the browsing events text box.
            browsingEventsTextBox.Text += $"{NameOf(UABrowseControl.CurrentNodeChanged)}; {uaBrowseControl1.Outputs.CurrentNodeElement}" + Environment.NewLine
        End Sub

        Private Sub uaBrowseControl1_NodeDoubleClick(sender As Object, e As EventArgs) Handles uaBrowseControl1.NodeDoubleClick
            ' Append the event name to the browsing events text box.
            browsingEventsTextBox.Text += $"{NameOf(UABrowseControl.NodeDoubleClick)}" + Environment.NewLine
        End Sub

        Private Sub uaBrowseControl1_SelectionChanged(sender As Object, e As EventArgs) Handles uaBrowseControl1.SelectionChanged
            ' Append the event name to the browsing events text box.
            browsingEventsTextBox.Text += $"{NameOf(UABrowseControl.SelectionChanged)}" + Environment.NewLine
        End Sub

        Private Sub setInputsButton_Click(sender As Object, e As EventArgs) Handles setInputsButton.Click
            ' Set the current node to our pre-defined OPC UA server.
            uaBrowseControl1.InputsOutputs.CurrentNodeDescriptor.EndpointDescriptor = "opc.tcp://opcua.demo-this.com:51210/UA/SampleServer"
        End Sub
    End Class
End Namespace

CSharp
VB.NET

namespace UAFormsDocExamples._UABrowseControl
{
    partial class UsageForm
    {
        /// <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.uaBrowseControl1 = new OpcLabs.EasyOpc.UA.Forms.Browsing.UABrowseControl();
            this.setInputsButton = new System.Windows.Forms.Button();
            this.getOutputsButton = new System.Windows.Forms.Button();
            this.label1 = new System.Windows.Forms.Label();
            this.outputsTextBox = new System.Windows.Forms.TextBox();
            this.browsingEventsTextBox = new System.Windows.Forms.TextBox();
            ((System.ComponentModel.ISupportInitialize)(this.uaBrowseControl1)).BeginInit();
            this.SuspendLayout();
            // 
            // uaBrowseControl1
            // 
            this.uaBrowseControl1.Location = new System.Drawing.Point(13, 42);
            this.uaBrowseControl1.MinimumSize = new System.Drawing.Size(135, 150);
            this.uaBrowseControl1.Name = "uaBrowseControl1";
            this.uaBrowseControl1.Size = new System.Drawing.Size(450, 300);
            this.uaBrowseControl1.TabIndex = 0;
            this.uaBrowseControl1.BrowseFailure += new OpcLabs.BaseLib.FailureEventHandler(this.uaBrowseControl1_BrowseFailure);
            this.uaBrowseControl1.CurrentNodeChanged += new System.EventHandler(this.uaBrowseControl1_CurrentNodeChanged);
            this.uaBrowseControl1.NodeDoubleClick += new System.EventHandler(this.uaBrowseControl1_NodeDoubleClick);
            this.uaBrowseControl1.SelectionChanged += new System.EventHandler(this.uaBrowseControl1_SelectionChanged);
            // 
            // setInputsButton
            // 
            this.setInputsButton.Location = new System.Drawing.Point(13, 13);
            this.setInputsButton.Name = "setInputsButton";
            this.setInputsButton.Size = new System.Drawing.Size(75, 23);
            this.setInputsButton.TabIndex = 1;
            this.setInputsButton.Text = "&Set inputs";
            this.setInputsButton.UseVisualStyleBackColor = true;
            this.setInputsButton.Click += new System.EventHandler(this.setInputsButton_Click);
            // 
            // getOutputsButton
            // 
            this.getOutputsButton.Location = new System.Drawing.Point(13, 349);
            this.getOutputsButton.Name = "getOutputsButton";
            this.getOutputsButton.Size = new System.Drawing.Size(75, 23);
            this.getOutputsButton.TabIndex = 2;
            this.getOutputsButton.Text = "&Get outputs";
            this.getOutputsButton.UseVisualStyleBackColor = true;
            this.getOutputsButton.Click += new System.EventHandler(this.getOutputsButton_Click);
            // 
            // label1
            // 
            this.label1.AutoSize = true;
            this.label1.Location = new System.Drawing.Point(481, 42);
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(88, 13);
            this.label1.TabIndex = 3;
            this.label1.Text = "&Browsing events:";
            // 
            // outputsTextBox
            // 
            this.outputsTextBox.Location = new System.Drawing.Point(13, 379);
            this.outputsTextBox.Multiline = true;
            this.outputsTextBox.Name = "outputsTextBox";
            this.outputsTextBox.ReadOnly = true;
            this.outputsTextBox.Size = new System.Drawing.Size(951, 59);
            this.outputsTextBox.TabIndex = 4;
            // 
            // browsingEventsTextBox
            // 
            this.browsingEventsTextBox.Location = new System.Drawing.Point(484, 59);
            this.browsingEventsTextBox.Multiline = true;
            this.browsingEventsTextBox.Name = "browsingEventsTextBox";
            this.browsingEventsTextBox.ReadOnly = true;
            this.browsingEventsTextBox.Size = new System.Drawing.Size(480, 283);
            this.browsingEventsTextBox.TabIndex = 5;
            // 
            // UsageForm
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(976, 450);
            this.Controls.Add(this.browsingEventsTextBox);
            this.Controls.Add(this.outputsTextBox);
            this.Controls.Add(this.label1);
            this.Controls.Add(this.getOutputsButton);
            this.Controls.Add(this.setInputsButton);
            this.Controls.Add(this.uaBrowseControl1);
            this.Name = "UsageForm";
            this.Text = "UsageForm";
            ((System.ComponentModel.ISupportInitialize)(this.uaBrowseControl1)).EndInit();
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion

        private OpcLabs.EasyOpc.UA.Forms.Browsing.UABrowseControl uaBrowseControl1;
        private System.Windows.Forms.Button setInputsButton;
        private System.Windows.Forms.Button getOutputsButton;
        private System.Windows.Forms.Label label1;
        private System.Windows.Forms.TextBox outputsTextBox;
        private System.Windows.Forms.TextBox browsingEventsTextBox;
    }
}

Namespace UAFormsDocExamples._UABrowseControl
    <Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()>
    Partial Class UsageForm
        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.uaBrowseControl1 = New OpcLabs.EasyOpc.UA.Forms.Browsing.UABrowseControl()
            Me.setInputsButton = New System.Windows.Forms.Button()
            Me.getOutputsButton = New System.Windows.Forms.Button()
            Me.label1 = New System.Windows.Forms.Label()
            Me.browsingEventsTextBox = New System.Windows.Forms.TextBox()
            Me.outputsTextBox = New System.Windows.Forms.TextBox()
            Me.uaBrowseControl1.BeginInit()
            Me.SuspendLayout()
            '
            'uaBrowseControl1
            '
            Me.uaBrowseControl1.Location = New System.Drawing.Point(13, 42)
            Me.uaBrowseControl1.MinimumSize = New System.Drawing.Size(135, 150)
            Me.uaBrowseControl1.Name = "uaBrowseControl1"
            Me.uaBrowseControl1.Size = New System.Drawing.Size(450, 300)
            Me.uaBrowseControl1.TabIndex = 0
            '
            'setInputsButton
            '
            Me.setInputsButton.Location = New System.Drawing.Point(13, 13)
            Me.setInputsButton.Name = "setInputsButton"
            Me.setInputsButton.Size = New System.Drawing.Size(75, 23)
            Me.setInputsButton.TabIndex = 1
            Me.setInputsButton.Text = "&Set inputs"
            Me.setInputsButton.UseVisualStyleBackColor = True
            '
            'getOutputsButton
            '
            Me.getOutputsButton.Location = New System.Drawing.Point(13, 349)
            Me.getOutputsButton.Name = "getOutputsButton"
            Me.getOutputsButton.Size = New System.Drawing.Size(75, 23)
            Me.getOutputsButton.TabIndex = 2
            Me.getOutputsButton.Text = "&Get outputs"
            Me.getOutputsButton.UseVisualStyleBackColor = True
            '
            'label1
            '
            Me.label1.AutoSize = True
            Me.label1.Location = New System.Drawing.Point(481, 42)
            Me.label1.Name = "label1"
            Me.label1.Size = New System.Drawing.Size(88, 13)
            Me.label1.TabIndex = 3
            Me.label1.Text = "Browsing &events:"
            '
            'browsingEventsTextBox
            '
            Me.browsingEventsTextBox.Location = New System.Drawing.Point(484, 59)
            Me.browsingEventsTextBox.Multiline = True
            Me.browsingEventsTextBox.Name = "browsingEventsTextBox"
            Me.browsingEventsTextBox.ReadOnly = True
            Me.browsingEventsTextBox.ScrollBars = System.Windows.Forms.ScrollBars.Vertical
            Me.browsingEventsTextBox.Size = New System.Drawing.Size(480, 283)
            Me.browsingEventsTextBox.TabIndex = 5
            '
            'outputsTextBox
            '
            Me.outputsTextBox.Location = New System.Drawing.Point(13, 379)
            Me.outputsTextBox.Multiline = True
            Me.outputsTextBox.Name = "outputsTextBox"
            Me.outputsTextBox.ReadOnly = True
            Me.outputsTextBox.Size = New System.Drawing.Size(951, 59)
            Me.outputsTextBox.TabIndex = 4
            '
            'UsageForm
            '
            Me.AutoScaleDimensions = New System.Drawing.SizeF(6.0!, 13.0!)
            Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
            Me.ClientSize = New System.Drawing.Size(976, 450)
            Me.Controls.Add(Me.browsingEventsTextBox)
            Me.Controls.Add(Me.outputsTextBox)
            Me.Controls.Add(Me.label1)
            Me.Controls.Add(Me.getOutputsButton)
            Me.Controls.Add(Me.setInputsButton)
            Me.Controls.Add(Me.uaBrowseControl1)
            Me.Name = "UsageForm"
            Me.Text = "Usage"
            Me.uaBrowseControl1.EndInit()
            Me.ResumeLayout(False)
            Me.PerformLayout()

        End Sub

        Friend WithEvents uaBrowseControl1 As OpcLabs.EasyOpc.UA.Forms.Browsing.UABrowseControl
        Friend WithEvents setInputsButton As Button
        Friend WithEvents getOutputsButton As Button
        Friend WithEvents label1 As Label
        Friend WithEvents outputsTextBox As TextBox
        Friend WithEvents browsingEventsTextBox As TextBox
    End Class
End Namespace

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

Reference

UABrowseNodeElement Class
UABrowseNodeElement Members

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