class Program { static async Task Main(string[] args) { var services = new ServiceCollection(); services.AddMqttFxClient(options => { options.Host = "broker.emqx.io"; options.Port = 1883; }); var container = services.BuildServiceProvider(); var client = container.GetService<MqttClient>(); client.ConnectedAsync += async e => { Console.WriteLine("### CONNECTED WITH SERVER ###"); Console.WriteLine("### SUBSCRIBED ###"); var subscriptionRequests = new SubscriptionRequestsBuilder() .WithTopicFilter(f => f.WithTopic("testtopic/a")) .WithTopicFilter(f => f.WithTopic("testtopic/b").WithAtLeastOnceQoS()) .Build(); var subscribeResult = await client.SubscribeAsync(subscriptionRequests); foreach (var item in subscribeResult.Items) { Console.WriteLine($"+ ResultCode = {item.ResultCode}"); } }; client.ApplicationMessageReceivedAsync += async message => { Console.WriteLine("### RECEIVED APPLICATION MESSAGE ###"); Console.WriteLine($"+ Topic = {message.Topic}"); Console.WriteLine($"+ Payload = {Encoding.UTF8.GetString(message.Payload)}"); Console.WriteLine($"+ QoS = {message.Qos}"); Console.WriteLine($"+ Retain = {message.Retain}"); Console.WriteLine(); await Task.CompletedTask; }; var connectResult = await client.ConnectAsync(); if (connectResult.Succeeded) { for (int i = 1; i <= 3; i++) { await Task.Delay(500); Console.WriteLine("### Publish Message ###"); var mesage = new ApplicationMessageBuilder() .WithTopic("testtopic/ab") .WithPayload($"HelloWorld: {i}") .WithQos(MqttQos.AtLeastOnce) .Build(); await client.PublishAsync(mesage); } } else Console.WriteLine("Connect Fail!"); Console.ReadKey(); } }