Azure ServiceBus 在 Client.Receive() 上返回 null

Question

我在从天蓝色中设置的队列接收消息时遇到问题。 我之前已经使用相同的代码成功完成了此操作，但现在当我尝试获取消息时，我只是得到 null。 当我在 azure 管理控制台中查看队列时，我清楚地看到该队列包含 5 条消息。

这是代码：

ServiceBus SB = new ServiceBus();
Microsoft.ServiceBus.Messaging.BrokeredMessage message;
while (true)
{
    message = SB.ReceiveMessage("orders");
    if (message == null)
    {
        break;
    }
    Procurement.Order order = message.GetBody<Procurement.Order>();
    order.id = Guid.NewGuid().ToString();
    order.remindercount = 0;

    using (DbManager db = new DbManager())
    {
        if (db.SetSpCommand("CreateOrderHead",
            db.Parameter("@companyId", order.companyId),
            db.Parameter("@orderId", order.orderId),
            db.Parameter("@suppliercode", order.suppliercode),
            db.Parameter("@supplierorderId", order.supplierorderId),
            db.Parameter("@orderdate", order.orderdate),
            db.Parameter("@desireddate", order.desireddate),
            db.Parameter("@ordertext", order.ordertext),
            db.Parameter("@name", order.name),
            db.Parameter("@street", order.street),
            db.Parameter("@zip", order.zip),
            db.Parameter("@city", order.city),
            db.Parameter("@country", order.country),
            db.Parameter("@countrycode", order.countrycode),
            db.Parameter("@deliveryterms", order.deliveryterms),
            db.Parameter("@reference", order.reference),
            db.Parameter("@deliveryinstruction", order.deliveryinstruction),
            db.Parameter("@id", order.id),
            db.Parameter("@partycode", order.partyCode)
            ).ExecuteNonQuery() == 1)
        {
            message.Complete();
            message = null;
        }

        db.SetSpCommand("DeleteOrderRows",
            db.Parameter("@orderid", order.orderId),
            db.Parameter("@companyId", order.companyId)
            ).ExecuteNonQuery();

        foreach (Procurement.Orderrow r in order.Orderrows)
        {
            db.SetSpCommand("CreateOrderRow",
            db.Parameter("@companyId", r.companyId),
            db.Parameter("@orderId", r.orderId),
            db.Parameter("@orderrowId", r.orderrowId),
            db.Parameter("@itemId", r.itemId),
            db.Parameter("@itemdesc", r.itemdesc),
            db.Parameter("@orderqty", r.orderqty),
            db.Parameter("@desireddate", r.desireddate),
            db.Parameter("@rowtext", r.rowtext),
            db.Parameter("@supplieritemId", r.supplieritemId),
            db.Parameter("@unit", r.unit),
            db.Parameter("@id", order.id),
            db.Parameter("@unitprice", r.unitprice),
            db.Parameter("@rowprice", r.rowprice)
            ).ExecuteNonQuery();
        }
    }
}
Thread.Sleep(new TimeSpan(0, 1, 0));

这是 ServiceBus 类：

public class ServiceBus
{
    TokenProvider TokenProvider;
    MessagingFactory Factory;

    public ServiceBus()
    {
        TokenProvider = TokenProvider.CreateSharedSecretTokenProvider(GetIssuerName(), GetSecret());
        Factory = MessagingFactory.Create(
            GetURINameSpace(),
            TokenProvider
            );
    }

    public void SendMessage(string queue, BrokeredMessage message)
    {
        var client = Factory.CreateQueueClient(queue);
        client.Send(message);
    }

    public BrokeredMessage ReceiveMessage(string queue)
    {
        var client = Factory.CreateQueueClient(queue, ReceiveMode.ReceiveAndDelete);
        BrokeredMessage message = client.Receive();
        return message;
    }

    private static Uri GetURINameSpace()
    {
        return ServiceBusEnvironment.CreateServiceUri("sb", GetNamespace(), string.Empty);
    }

    private static string GetNamespace()
    {
        return "Namespace i have verified its the right one";
    }

    private static string GetIssuerName()
    {
        return "Issuer i have verified its the right one";
    }

    private static string GetSecret()
    {
        return "Key i have verified its the right one";
    }
}

我认为这应该非常简单，但我无法找出我做错了什么。 这可能是我缺少的一些小东西......

无论如何，提前感谢！

Answer 1

您在 SubcriptionDescription.MessageCount 中看到的那些 BrokeredMessage 不仅是常规消息，而且还是 $DeadLetterQueue-sub 队列中的消息计数！

使用此代码片段检索该子队列中的所有消息并打印出其详细信息。将 [主题] 和 [订阅] 重命名为您实际的：

MessagingFactory msgFactory = MessagingFactory.Create(_uri, _tokenProvider);
        MessageReceiver msgReceiver = msgFactory.CreateMessageReceiver("[topic]/subscriptions/[subscription]/$DeadLetterQueue", ReceiveMode.PeekLock);

        while (true)
        {
            BrokeredMessage msg = msgReceiver.Receive();

            if (msg != null)
            {
                Console.WriteLine("Deadlettered message.");

                Console.WriteLine("MessageId:                  {0}", msg.MessageId);
                Console.WriteLine("DeliveryCount:              {0}", msg.DeliveryCount);
                Console.WriteLine("EnqueuedTimeUtc:            {0}", msg.EnqueuedTimeUtc);
                Console.WriteLine("Size:                       {0} bytes", msg.Size);
                Console.WriteLine("DeadLetterReason:           {0}",
                    msg.Properties["DeadLetterReason"]);
                Console.WriteLine("DeadLetterErrorDescription: {0}",
                    msg.Properties["DeadLetterErrorDescription"]);
                Console.WriteLine();
                msg.Complete();
            }
        }

Answer 2

此问题的解决方案要么是天蓝色管理门户中的错误，使其显示队列上错误的消息数量，要么消息以某种方式被标记，以便它们不会被读取。
换句话说，它一直有效，我只需向队列添加一些新消息即可。