How to listen to the serialized Azure Message Bus message in c#?

Question

I am using the Azure Message Bus to communicate with my microservices. I am able to send the message under the topic Account Updated from service A. However, the message is not being read by another service called B. I mean if I send "Hello" string, it is being read properly. But the serialized message is not being decoded at the listener.

Here is the message that is sent from service A:

var invoiceMessage = new InvoiceMessageDto<AccountInvoicingMessageDto>
                {
                    MessageType = MessageType.Create,
                    InvoiceType = InvoiceType.Account,
                    CreationDateTime = DateTime.Now,
                    MessageDto = new AccountInvoicingMessageDto
                    {
                        AccountId = request.Id,
                        OrganizationName = request.OrganizationName,
                        AccountStatus = AccountStatusEnum.ApprovedPendingPayment,
                        FlatFee = flatfee
                    }
                };
                
                try
                {
                    Console.WriteLine("Success Success when sending Account Message");
                    _logger.LogInformation($"Success when sending Account Update Message");
                    _azServiceBusConsumer.SendMessage(invoiceMessage, MessageTopics.ACCOUNT_UPDATED);
                }
                catch (Exception ex)
                {
                    _logger.LogInformation($"Error when sending Message: {ex}");
                }

The _azServiceBusConsumer is an instance of the interface IAzServiceBusConsumer as shown below:

namespace Services.Common.Interface
{
    public interface IAzServiceBusConsumer
    {

        void Start();
        void Stop();

        void SendMessage(IntegrationBaseMessage message, string? topicName);

    }
}

And here is how I am listening to it in service B:

_receiverClient is defined as:

 _receiverClient = new SubscriptionClient(_config["MessageBus:ConnectionString"],
                                                     MessageTopics.ACCOUNT_UPDATED,
                                                     _config["MessageBus:SubscriptionName"],
                                                     ReceiveMode.PeekLock,
                                                     RetryPolicy.Default);

And then it is used by the listener as:

_receiverClient.RegisterMessageHandler(async (message, cancelToken) =>
            {
                var bodyBytes = message.Body;
                var ourMessage = Encoding.UTF8.GetString(bodyBytes);

                _logger.LogInformation($"Received: {ourMessage}");
}

When checked in the debug mode, the message variable shows the message that is received but bodyBytes shows nothing when the mouse is hovered there.

So, how should I decode the message received by my listener (service B)?

Any help would be more than appreciable.

Answer 1

The RegisterMessageHandler method of queue is used to register the function that will process the message. This method expects two parameters: handler and message handler option. something like :

// Configure the MessageHandler Options in terms of exception handling, number of concurrent messages to deliver etc.  
    var messageHandlerOptions = new MessageHandlerOptions(ExceptionReceivedHandler)  
    {  
        MaxConcurrentCalls = 1,  
        AutoComplete = false  
    };  
  
    // Register the function that will process messages 

    queueClient.RegisterMessageHandler(await queueClient.CompleteAsync(message.SystemProperties.LockToken), messageHandlerOptions);

and after that your queueClient ready for call CloseAsync() liek

  queueClient.CloseAsync().Wait();

and your sender should be something like

  var message = new Message(Encoding.UTF8.GetBytes(messageBody));  
 await queueClient.SendAsync(message);