OPC Studio User's Guide and Reference
UAFolder Class
Members  Example 



OpcLabs.ServerOpcUA Assembly > OpcLabs.EasyOpc.UA.NodeSpace Namespace : UAFolder Class
Represents a folder in OPC Unified Architecture node space of the OPC server.
Object Model
UAFolder ClassUAServerNode Class
Syntax
'Usage
 
Dim instance As UAFolder
Remarks

Folders in OPC UA serve as organizational units that can contain variables, other folders, or both. They help in structuring the node space of an OPC UA server in a hierarchical manner, making it easier for clients to browse and interact with the server's address space.

If you are doing client development as well, an instance of UAFolder can be implicitly converted to a OpcLabs.EasyOpc.UA.UANodeDescriptor, which means that it can be directly used in place of OpcLabs.EasyOpc.UA.UANodeDescriptor parameters anywhere in the client code. If your language does not support implicit conversion operators, use the UAServerNode.EffectiveNodeDescriptor property instead.

Example
// This example shows how to folders nested in another folders.
// 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-OPCStudio-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._UAFolder
{
    class _Building
    {
        public static void Nested()
        {
            // Instantiate the server object.
            // By default, the server will run on endpoint URL "opc.tcp://localhost:48040/".
            var server = new EasyUAServer();

            // Create a structure where a folder contains another folders, and the nested folders contains data variables.
            server.Add(new UAFolder("Folder1")
            {
                new UAFolder("NestedFolder1")
                {
                    new UADataVariable("Constant").ConstantValue(42)
                },
                new UAFolder("NestedFolder2"),
                new UADataVariable("Constant").ConstantValue("abc")
            });
            server.Add(new UAFolder("Folder2"));

            // Start the server.
            Console.WriteLine("The server is starting...");
            server.Start();

            Console.WriteLine("The server is started.");
            Console.WriteLine();

            // Let the user decide when to stop.
            Console.WriteLine("Press Enter to stop the server...");
            Console.ReadLine();

            // Stop the server.
            Console.WriteLine("The server is stopping...");
            server.Stop();

            Console.WriteLine("The server is stopped.");
        }
    }
}
' This example shows how to folders nested in another folders.
' 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 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 System
Imports OpcLabs.EasyOpc.UA
Imports OpcLabs.EasyOpc.UA.NodeSpace

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

            ' Create a structure where a folder contains another folders, and the nested folders contains data variables.
            server.Add(New UAFolder("UAFolder") From
            {
                New UAFolder("NestedFolder1") From
                {
                    New UADataVariable("Constant").ConstantValue(42)
                },
                New UAFolder("NestedFolder2"),
                New UADataVariable("Constant").ConstantValue("abc")
            })
            server.Add(New UAFolder("Folder2"))

            ' Start the server.
            Console.WriteLine("The server is starting...")
            server.Start()

            Console.WriteLine("The server is started.")
            Console.WriteLine()

            ' Let the user decide when to stop.
            Console.WriteLine("Press Enter to stop the server...")
            Console.ReadLine()

            ' Stop the server.
            Console.WriteLine("The server is stopping...")
            server.Stop()

            Console.WriteLine("The server is stopped.")
        End Sub
    End Class
End Namespace
Inheritance Hierarchy

System.Object
   System.MarshalByRefObject
      System.ComponentModel.Component
         OpcLabs.BaseLib.Widgets.Widget
            OpcLabs.BaseLib.NodeSpace.Node
               OpcLabs.BaseLib.NodeSpace.NodeFrontEnd
                  OpcLabs.EasyOpc.UA.NodeSpace.UAServerNode
                     OpcLabs.EasyOpc.UA.NodeSpace.UAFolder

Requirements

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

See Also