Error when listening for Azure Service Bus queue messages in ASP.Net Core app controller

Following along in this Azure Service Bus Tutorial I've taken the code and mostly pasted it into my ASP.Net Core app controller 'MyController.cs', I'm not following the tutorial verbatim with a console app because I already have a website where I want to send and receive messages.

I can send messages to the queue correctly, but after I implemented the code to listen for and receive messages, I start continually receiving errors in the 'ErrorHandler()' method that says:

System.ObjectDisposedException: AmqpConnectionScope has already been closed and cannot perform the requested operation.

QUESTIONS -

1. Is this the correct code below needed to listen for incoming messages in a ASP.Net Core app controller? I looked through the docs but can't seem to find any other examples that might handle this scenario?
2. I do see a code sample where MS is using an Azure function to listen for incoming service bus messages. Is that the prescribed way to listen if I'm not using a console app? I assumed it would be easier to have all code (sending/receiving) in one application?

Here is all the code from my controller related to service bus calls. FYI - I've commented out 'StopProcessingAsync()' as it seems like it wasn't needed to perform my testing.

    [HttpPost("test")]      public async Task<IActionResult> OnTesting(TestDto testDto)      {           // some code here left out           await SendMessageAsync();           await ReceiveMessagesAsync();      }        static async Task SendMessageAsync()      {          var connectionString = "my secret conn string";          var queueName = "testqueue";            // create a Service Bus client           await using (ServiceBusClient client = new ServiceBusClient(connectionString))          {              // create a sender for the queue               ServiceBusSender sender = client.CreateSender(queueName);                // create a message that we can send              ServiceBusMessage message = new ServiceBusMessage("Hello world!");                // send the message              await sender.SendMessageAsync(message);              Console.WriteLine($"Sent a single message to the queue: {queueName}");          }      }        static async Task ReceiveMessagesAsync()      {          var connectionString = "same as above conn string";          var queueName = "testqueue";            await using (ServiceBusClient client = new ServiceBusClient(connectionString))          {              // create a processor that we can use to process the messages              ServiceBusProcessor processor = client.CreateProcessor(queueName, new ServiceBusProcessorOptions());                // add handler to process messages              processor.ProcessMessageAsync += MessageHandler;                // add handler to process any errors              processor.ProcessErrorAsync += ErrorHandler;                // start processing               await processor.StartProcessingAsync();                // Console.WriteLine("Wait for a minute and then press any key to end the processing");              // Console.ReadKey();                // stop processing               // Console.WriteLine("\nStopping the receiver...");              // await processor.StopProcessingAsync();              // Console.WriteLine("Stopped receiving messages");          }      }        // handle received messages      static async Task MessageHandler(ProcessMessageEventArgs args)      {          string body = args.Message.Body.ToString();          Console.WriteLine($"Received: {body}");            // complete the message. messages is deleted from the queue.           await args.CompleteMessageAsync(args.Message);      }        // handle any errors when receiving messages      static Task ErrorHandler(ProcessErrorEventArgs args)      {          Console.WriteLine(args.Exception.ToString()); // errors coming in after listening starts          return Task.CompletedTask;      }  

https://stackoverflow.com/questions/67351828/error-when-listening-for-azure-service-bus-queue-messages-in-asp-net-core-app-co May 02, 2021 at 07:49AM