Develop the subscriber NetLogic and interface

Develop a NetLogic and integrate it with the interface.
  1. Develop the NetLogic
  2. Right-click
    MainWindow (type)
     and select
    New
    Runtime NetLogic
    .
  3. Hover-over the NetLogic, select
    Edit
    , and enter
    SubscriberLogic
    .
  4. Double-click the NetLogic.
    The external code editor opens.
  5. In the code editor, replace the existing code with the following code:
    #region StandardUsing
using System;
using FTOptix.CoreBase;
using FTOptix.HMIProject;
using UAManagedCore;
using OpcUa = UAManagedCore.OpcUa;
using FTOptix.NetLogic;
using FTOptix.UI;
using FTOptix.OPCUAServer;
#endregion
using uPLibrary.Networking.M2Mqtt;
using uPLibrary.Networking.M2Mqtt.Messages;

public class SubscriberLogic : BaseNetLogic
{
    public override void Start()
    {
        var brokerIpAddressVariable = Project.Current.GetVariable("Model/BrokerIpAddress");

        // Create a client connecting to the broker (default port is 1883)
        subscribeClient = new MqttClient(brokerIpAddressVariable.Value);
        // Connect to the broker
        subscribeClient.Connect("
    SubscriberClient
    ");
        // Assign a callback to be executed when a message is received from the broker
        subscribeClient.MqttMsgPublishReceived += SubscribeClientMqttMsgPublishReceived;
        // Subscribe to the "my_topic" topic with QoS 2
        ushort msgId = subscribeClient.Subscribe(new string[] { "/my_topic" }, // topic
            new byte[] { MqttMsgBase.QOS_LEVEL_EXACTLY_ONCE }); // QoS level

        messageVariable = Project.Current.GetVariable("Model/Message");
    }

    public override void Stop()
    {
        subscribeClient.Unsubscribe(new string[] { "/my_topic" });
        subscribeClient.Disconnect();
    }

    private void SubscribeClientMqttMsgPublishReceived(object sender, MqttMsgPublishEventArgs e)
    {
        messageVariable.Value = "Message received: " + System.Text.Encoding.UTF8.GetString(e.Message);
    }

    private MqttClient subscribeClient;
    private IUAVariable messageVariable;
}
  6. Save the code.
  7. Create the interface elements
  8. Create the message variable by performing the following actions:
    1. In
      Project view
      , right-click
      Model
       and select
      New
      Variable
      .
    2. Hover-over the variable, select
      Edit
      , and enter
      Message
      .
    3. In
      Properties
      , select
      Int32
       and select
      String
      .
  9. Create the Subscribe label by performing the following actions:
    1. In
      Project view
      , right-click
      MainWindow (type)
       and select
      New
      Base controls
      Label
      .
    2. Hover-over the label, select
      Edit
      , and enter
      SubscribeLabel
      .
    3. In
      Properties
      , create a dynamic link between
      Text
       and the
      Message
       variable.
      For more information about dynamic links, see Create dynamic links.
  10. Arrange the interface elements.
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