ProcessMessagesAsync方法未在Azure服务总线订阅中激发

Question

    public async Task GetMessageFromSubscription()
        {

        subscriptionClient = new SubscriptionClient(ServiceBusConnectionString, TopicName, SubscriptionName);

                RegisterOnMessageHandlerAndReceiveMessages();
                //  Console.Read();  ------- Without this line 

                await subscriptionClient.CloseAsync();
           }

 public void RegisterOnMessageHandlerAndReceiveMessages()
        {
            var messageHandlerOptions = new MessageHandlerOptions(ExceptionReceivedHandler);
            subscriptionClient.RegisterMessageHandler(ProcessMessagesAsync, messageHandlerOptions);
         }


        private async Task ProcessMessagesAsync(Message message, CancellationToken token)
        {
               var messageBody = Encoding.UTF8.GetString(message.Body);
                var serviceBusMessage = JsonConvert.DeserializeObject<WorkIntakeItem>(messageBody);
                await subscriptionClient.CompleteAsync(message.SystemProperties.LockToken);

         }

Answer 1

它是一个循环，随着进程的运行而运行。当进程结束时，处理程序将终止。

如果您有一个持续的消息流，处理程序（也称为消息泵）是一个合适的选项。如果您只需要接收一条消息并退出，那么就会有messageReceiver.receiveAsync的阻塞选项。您可以控制应用程序何时关闭它。

static IMessageReceiver messageReceiver;
RegisterOnMessageHandlerAndReceiveMessages();
Message message = await messageReceiver.ReceiveAsync();
await messageReceiver.CompleteAsync(message.SystemProperties.LockToken);
await messageReceiver.CloseAsync();
await subscriptionClient.CloseAsync();

有关更多详细信息，您可以参考本文。