服务总线队列如何将任务<BrokeredMessage>映射到任务<MyClass>

Question

我正在为服务总线队列使用适配器。因此，我不应该使用任何Queue类作为返回类型。但我被ReceiveAsync()方法卡住了。如何映射Task<BrokeredMessage> to Task<MyAdapterClass>？

这是BrokeredMessage 的适配器类

public class QueueMessage : IQueueMessage
    {
        private BrokeredMessage _message;
        public T Body<T>()
        {
            T result = default(T);
            if (_message != null)
                result = _message.GetBody<T>();
            return result;
        }
        public BrokeredMessage Message { set { _message = value; } }
        public string Label
        {
            get
            {
                var result = "";
                if (_message != null)
                    result = _message.Label;
                return result;
            }
        }
        public void MoveToDeadLetter()
        {
            if (_message != null)
                _message.DeadLetter();
        }
        public void Complete()
        {
            if (_message != null)
                _message.Complete();
        }

        public async void CompleteAsync()
        {
            if (_message != null)
                await _message.CompleteAsync();
        }
        public async void AbandonAsync()
        {
            if (_message != null)
                await _message.AbandonAsync();
        }
        public void Abandon()
        {
            if (_message != null)
                _message.Abandon();
        }
        public string MessageId
        {
            get
            {
                return _message == null ? null : _message.MessageId;
            }
            set { if (_message != null) _message.MessageId = value; }
        }
        public string CorrelationId
        {
            get
            {
                return _message == null ? null : _message.CorrelationId;
            }
            set { if (_message != null) _message.CorrelationId = value; }
        }
        public int DeliveryCount { get { return _message == null ? -1 : _message.DeliveryCount; } }
    }

我想要像这样的方法

 public  Task<IQueueMessage> ReceiveAsync(TimeSpan serverWaitTime)
        {
            Task<QueueMessage> task= QueueClient.ReceiveAsync(serverWaitTime);
            return task;
        }

在驱动程序项目上，我想使用这样的任务：

 var task1 = _queueAdapter.ReceiveAsync(new TimeSpan(200)).ContinueWith(ReadMessageAsync);

Answer 1

我会尝试在QueueClient.ReceiveAsync（）上继续。请参阅https://msdn.microsoft.com/en-us/library/vstudio/ee372288（v=vs.100）.aspx

public Task<IQueueMessage> ReceiveAsync(TimeSpan serverWaitTime)
{
    Task<QueueMessage> task = QueueClient
                              .ReceiveAsync(serverWaitTime)
                              .ContinueWith(bm => new QueueMessage{Message = bm});
    return task;
}

Answer 2

谢谢Richard。我刚刚改进了你的答案，效果很好。

public async Task<IQueueMessage> ReceiveAsycn(TimeSpan serverWaitTime)
        {
            var task = QueueClient
                                      .ReceiveAsync(serverWaitTime)
                                      .ContinueWith(bm => bm.Result==null ? null : new QueueMessage { Message=bm.Result});
            return await task;
        }