c# - 在 OnMessageOptions 中使用 ExceptionReceived

Question

我正在尝试使用方法 QueueClient.OnMessage(Action<BrokeredMessage>, OnMessageOptions) 。在 OnMessageOptions我编写了这个简单的ExceptionReceived事件:

void LogErrors(object sender, ExceptionReceivedEventArgs e)
{
  if (e.Exception != null)
  {
    Trace.TraceError("Exception captured: " + e.Exception.Message);
  }
}

我的疑问是如何获取“LogErrors”BrokeredMessage这是在回调中进行处理的，以便在发生 BrokeredMessage 时保存包含错误的日志。

Answer 1

我试图了解如何从 ExceptionReceived 回调中/在 ExceptionReceived 回调中获取消息，但参数中不存在该信息。这是我的示例代码:

var connectionString = "my-connection-string";
var queueName = "my-queue-name";
var client = QueueClient.CreateFromConnectionString(connectionString, queueName);

var options = new OnMessageOptions();
options.ExceptionReceived += (sender, args) =>
{
    // Neither sender or args contains information about the message being processed
};

client.OnMessage(brokeredMessage =>
{
    throw new Exception();
}, options);

根据您的需要，简单的解决方案是将回调包装在 try/catch 中:

client.OnMessage(brokeredMessage =>
{
    try
    {
        // Process the message
        ...

       // Complete the message (depends on the )
       brokeredMessage.Complete();
    }
    catch (Exception ex)
    {

        Trace.TraceError("Exception captured: " + ex.Message);

        // Here you have access to the brokeredMessage so you can log what you want.
        ...    
        //Abandon the message so that it could be re-process ??
        brokeredMessage.Abandon();        
    }

}, options);

您可以将此包装器放入函数中或为 QueueClient 创建扩展方法后:

public static class QueueClientExtensions
{
    public static void OnCustomMessage(this QueueClient queueClient, Action<BrokeredMessage> callback,
        OnMessageOptions onMessageOptions)
    {
        queueClient.OnMessage(message =>
        {
            try
            {
                // process the message
                callback(message);

                //complete if success
                message.Complete();
            }
            catch (Exception ex)
            {
                // Here you have access to the brokeredMessage so you can log what you want.
                // message.GetBody<string>() 
                Trace.TraceError("Exception captured: " + ex.Message);

                //Abandon the message so that it could be re-process
                message.Abandon();
            }

        }, onMessageOptions);
    }
}

并以同样的方式调用该方法:

var queueClient = QueueClient.CreateFromConnectionString(connectionString, queueName);
queueClient.OnCustomMessage(brokeredMessage =>
{
    // Process the message
    ...
}, new OnMessageOptions());