SparkplugConnectionStateChangedEventHandler Delegate

Represents the method that will handle an event raised when the state of a connection to the Sparkplug system changed.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
Public Delegate Sub SparkplugConnectionStateChangedEventHandler( _
   ByVal sender As Object, _
   ByVal e As SparkplugConnectionStateChangedEventArgs _
)

'Usage
 
Dim instance As New SparkplugConnectionStateChangedEventHandler(AddressOf HandlerMethod)

public delegate void SparkplugConnectionStateChangedEventHandler( 
   object sender,
   SparkplugConnectionStateChangedEventArgs e
)

public delegate void SparkplugConnectionStateChangedEventHandler( 
   Object^ sender,
   SparkplugConnectionStateChangedEventArgs^ e
)

Parameters

sender: The source of the event.
e: A OpcLabs.EasySparkplug.OperationModel.SparkplugConnectionStateChangedEventArgs that contains the event data.

Remarks

This is the type of the ISparkplugSystemConnectionMonitoring.SystemConnectionStateChanged handler.

Sparkplug is a trademark of Eclipse Foundation, Inc. "MQTT" is a trademark of the OASIS Open standards consortium. Other related terms are trademarks of their respective owners. Any use of these terms on this site is for descriptive purposes only and does not imply any sponsorship, endorsement or affiliation.

Example

CSharp
VB.NET

// This example shows how to create a Sparkplug edge node with a single metric, start and stop it.
//
// You can use any Sparkplug application, including our SparkplugCmd utility and the SparkplugApplicationConsoleDemo
// program, to subscribe to the edge node data. 
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
// Sparkplug 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.EasySparkplug;
using OpcLabs.EasySparkplug.OperationModel;

namespace SparkplugDocExamples.EdgeNode._EasySparkplugEdgeNode
{
    partial class Start_Stop
    {
        static public void Main1()
        {
            // Note that the default port for the "mqtt" scheme is 1883.
            var hostDescriptor = new SparkplugHostDescriptor("mqtt://localhost");

            // Instantiate the edge node object and hook events.
            var edgeNode = new EasySparkplugEdgeNode(hostDescriptor, "easyGroup", "easySparkplugDemo");
            edgeNode.SystemConnectionStateChanged += edgeNode_Main1_SystemConnectionStateChanged;

            // Define a metric providing random integers.
            var random = new Random();
            edgeNode.Metrics.Add(new SparkplugMetric("MyMetric").ReadValueFunction(() => random.Next()));

            // Start the edge node.
            Console.WriteLine("The edge node is starting...");
            edgeNode.Start();

            Console.WriteLine("The edge node is started.");
            Console.WriteLine();

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

            // Stop the edge node.
            Console.WriteLine("The edge node is stopping...");
            edgeNode.Stop();

            Console.WriteLine("The edge node is stopped.");
        }


        static void edgeNode_Main1_SystemConnectionStateChanged(
            object sender, 
            SparkplugConnectionStateChangedEventArgs eventArgs)
        {
            // Display the new connection state (such as when the connection to the broker succeeds or fails).
            Console.WriteLine($"{nameof(EasySparkplugEdgeNode.SystemConnectionStateChanged)}: {eventArgs}");
        }
    }
}

' This example shows how to create a Sparkplug edge node with a single metric, start and stop it.
'
' You can use any Sparkplug application, including our SparkplugCmd utility and the SparkplugApplicationConsoleDemo
' program, to subscribe to the edge node data.
'
' Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-ConnectivityStudio/Latest/examples.html .
' Sparkplug 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.

Imports OpcLabs.EasySparkplug
Imports OpcLabs.EasySparkplug.OperationModel

Namespace Global.SparkplugDocExamples.EdgeNode._EasySparkplugEdgeNode
    Partial Class Start_Stop
        Public Shared Sub Main1()
            ' Note that the default port for the "mqtt" scheme is 1883.
            Dim hostDescriptor = New SparkplugHostDescriptor("mqtt://localhost")

            ' Instantiate the edge node object and hook events.
            Dim edgeNode = New EasySparkplugEdgeNode(hostDescriptor, "easyGroup", "easySparkplugDemo")
            AddHandler edgeNode.SystemConnectionStateChanged, AddressOf edgeNode_Main1_SystemConnectionStateChanged

            ' Define a metric providing random integers.
            Dim random = New Random()
            edgeNode.Metrics.Add(New SparkplugMetric("MyMetric").ReadValueFunction(Function() random.Next()))

            ' Start the edge node.
            Console.WriteLine("The edge node is starting...")
            edgeNode.Start()

            Console.WriteLine("The edge node is started.")
            Console.WriteLine()

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

            ' Stop the edge node.
            Console.WriteLine("The edge node is stopping...")
            edgeNode.Stop()

            Console.WriteLine("The edge node is stopped.")
        End Sub

        Private Shared Sub edgeNode_Main1_SystemConnectionStateChanged _
            (ByVal sender As Object, ByVal eventArgs As SparkplugConnectionStateChangedEventArgs)
            ' Display the new connection state (such as when the connection to the broker succeeds or fails).
            Console.WriteLine($"{NameOf(EasySparkplugEdgeNode.SystemConnectionStateChanged)}: {eventArgs}")
        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

SparkplugConnectionStateChangedEventHandler Members
OpcLabs.EasySparkplug Namespace
SystemConnectionStateChanged Event

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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.