MQTTnet/Source/MQTTnet.AspTestApp/Pages/Index.cshtml

@page
@model IndexModel
@{
    ViewData["Title"] = "Home page";
}

<div>
    <h1>MQTTnet ASP.NET Core Test App</h1>
</div>

<script src="https://unpkg.com/mqtt/dist/mqtt.min.js"></script>

<script>
    const options = {
      clean: true,
      connectTimeout: 4000,
      clientId: 'mqttnet_web_client'
    }

    const client  = mqtt.connect('ws://localhost:5000/mqtt')

    client.on('connect', function () {
      console.log('Connected')
      client.subscribe('#', function (err) {
        if (!err) {
          client.publish('test', 'Hello mqtt')
        }
      })
    })

    client.on('message', function (topic, message) {
      console.log(message.toString())
    })
</script>