Item Property (UAServerNode)

Indexer to get a sub-node by name.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<JetBrains.Annotations.NotNullAttribute()>
Public ReadOnly Default Property Item( _
   ByVal nodeName As String _
) As UAServerNode

'Usage
 
Dim instance As UAServerNode
Dim nodeName As String
Dim value As UAServerNode
 
value = instance.Item(nodeName)

[JetBrains.Annotations.NotNull()]
public UAServerNode this[ 
   string nodeName
]; {get;}

[JetBrains.Annotations.NotNull()]
public:
property UAServerNode^ default [String^] {
   UAServerNode^ get(String^ nodeName);
}

Parameters

nodeName: The name of the sub-node to retrieve.

Property Value

The value of this property cannot be null (Nothing in Visual Basic).

The sub-node with the specified name.

Exceptions

Exception	Description
System.ArgumentNullException	Thrown when nodeName is null.
System.Collections.Generic.KeyNotFoundException	Thrown when a node with the specified name is not found.

Example

CSharp
PowerShell
VB.NET

// This example shows how sub-nodes of server nodes can be accessed by their node name using an indexer.
// You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server. 
//
// 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 OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.NodeSpace;

namespace UAServerDocExamples._UAServerNode
{
    class Indexer
    {
        public static void Main1()
        {
            // Instantiate the server object.
            // By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
            var server = new EasyUAServer();

            // Define some nodes in the server.
            UADataVariable constantDataVariable = UADataVariable.CreateIn(server.Objects, "Constant").ConstantValue("abc");
            UADataVariable nestedConstantDataVariable = UADataVariable.CreateIn(constantDataVariable, "NestedConstant").ConstantValue(42);
            
            // Get the nested constant data variable.
            UAServerNode serverNode1 = server.Objects["Constant"]["NestedConstant"];
            Console.WriteLine(serverNode1);
        }
    }
}

# This example shows how sub-nodes of server nodes can be accessed by their node name using an indexer.
# You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server. 
#
# Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/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.

#requires -Version 5.1
using namespace OpcLabs.EasyOpc.UA
using namespace OpcLabs.EasyOpc.UA.NodeSpace

# The path below assumes that the current directory is [ProductDir]/Examples-NET/PowerShell/Windows .
Add-Type -Path "../../../Components/Opclabs.QuickOpc/net472/OpcLabs.ServerOpcUAComponents.dll"

# Instantiate the server object.
# By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
$server = New-Object EasyUAServer

# Define some nodes in the server.
$constantDataVariable = [UADataVariableExtension]::ConstantValue([UADataVariable]::CreateIn($server.Objects, "Constant"), "abc")
$nestedConstantDataVariable = [UADataVariableExtension]::ConstantValue([UADataVariable]::CreateIn($constantDataVariable, "NestedConstant"), 42)

# Get the nested constant data variable.
$serverNode1 = $server.Objects["Constant"]["NestedConstant"]
Write-Host $serverNode1.ToString()

' This example shows how sub-nodes of server nodes can be accessed by their node name using an indexer.
' You can use any OPC UA client, including our Connectivity Explorer and OpcCmd utility, to connect to the server.
'
' 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 OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.NodeSpace

Namespace Global.UAServerDocExamples._UAServerNode
Partial Friend Class Indexer
Shared Sub Main1()
' Instantiate the server object.
' By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
Dim server = New EasyUAServer()

' Define some nodes in the server.
Dim constantDataVariable As UADataVariable = UADataVariable.CreateIn(server.Objects, "Constant").ConstantValue("abc")
Dim nestedConstantDataVariable As UADataVariable = UADataVariable.CreateIn(constantDataVariable, "NestedConstant").ConstantValue(42)

' Get the nested constant data variable.
Dim serverNode1 As UAServerNode = server.Objects("Constant")("NestedConstant")
Console.WriteLine(serverNode1)
End Sub
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

UAServerNode Class
UAServerNode Members

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Missing some example? Ask us for it on our Online Forums! You do not have to own a commercial license in order to use Online Forums, and we reply to every post.