IoTGateway.MQTTnet.Extensions.ManagedClient 5.0.0

MQTTnet.Extensions.ManagedClient

中文文档

MQTTnet.Extensions.ManagedClient is a managed MQTT client extension for MQTTnet 5.x. It keeps the client connection alive, reconnects automatically, restores subscriptions after reconnect, and publishes queued application messages from a managed queue.

Features

• Automatic reconnect with configurable delay.
• Managed publish queue through EnqueueAsync.
• Optional pending-message queue limit and overflow strategy.
• Subscription tracking with automatic resubscription after reconnect.
• Event hooks for connection, reconnect failures, subscription synchronization, skipped messages, processed messages, and received messages.
• Optional storage abstraction for queued messages.

Installation

After the package is published to NuGet:

dotnet add package IoTGateway.MQTTnet.Extensions.ManagedClient

Before publishing, reference the project directly:

<ProjectReference Include="..\MQTTnet.Extensions.ManagedClient\MQTTnet.Extensions.ManagedClient.csproj" />

Quick Start

using MQTTnet;
using MQTTnet.Extensions.ManagedClient;
using MQTTnet.Protocol;

var factory = new MqttClientFactory();
using var client = factory.CreateManagedMqttClient();

client.ConnectedAsync += args =>
{
    Console.WriteLine("Connected.");
    return Task.CompletedTask;
};

client.DisconnectedAsync += args =>
{
    Console.WriteLine("Disconnected.");
    return Task.CompletedTask;
};

client.ApplicationMessageReceivedAsync += args =>
{
    var payload = args.ApplicationMessage.ConvertPayloadToString();
    Console.WriteLine($"Received {args.ApplicationMessage.Topic}: {payload}");
    return Task.CompletedTask;
};

var options = new ManagedMqttClientOptionsBuilder()
    .WithAutoReconnectDelay(TimeSpan.FromSeconds(5))
    .WithMaxPendingMessages(1000)
    .WithPendingMessagesOverflowStrategy(MqttPendingMessagesOverflowStrategy.DropOldestQueuedMessage)
    .WithClientOptions(builder =>
    {
        builder
            .WithTcpServer("broker.hivemq.com", 1883)
            .WithClientId($"managed-client-{Guid.NewGuid():N}")
            .WithCleanSession();
    })
    .Build();

await client.StartAsync(options);
await client.SubscribeAsync("iotgateway/demo/managed-client", MqttQualityOfServiceLevel.AtLeastOnce);
await client.EnqueueAsync("iotgateway/demo/managed-client", "hello from managed client", MqttQualityOfServiceLevel.AtLeastOnce);

Demo

Run the demo project:

dotnet run --project src/MQTTnet.Extensions.ManagedClient.Demo/MQTTnet.Extensions.ManagedClient.Demo.csproj

Optional arguments:

dotnet run --project src/MQTTnet.Extensions.ManagedClient.Demo/MQTTnet.Extensions.ManagedClient.Demo.csproj -- --host broker.hivemq.com --port 1883 --topic iotgateway/demo/managed-client

The demo connects to the broker, subscribes to the configured topic, publishes messages through the managed queue, prints received messages, and stops cleanly when you press Ctrl+C.

Main API

• MqttClientFactory.CreateManagedMqttClient() creates the managed client.
• ManagedMqttClientOptionsBuilder builds reconnect, queue, storage, and MQTT client options.
• IManagedMqttClient.StartAsync(...) starts connection maintenance.
• IManagedMqttClient.EnqueueAsync(...) queues application messages for publishing.
• IManagedMqttClient.SubscribeAsync(...) and UnsubscribeAsync(...) manage subscriptions.
• IManagedMqttClient.StopAsync(...) stops publishing and disconnects.

License

This project is licensed under the MIT License.