无法序列化Azure ServiceBus消息 - 从“ExpiresAtUtc”获取值时出错

时间:2017-12-11 14:27:39

标签: c# json.net azureservicebus

我需要编写一个测试,我手动创建一个Microsoft.Azure.ServiceBus.Message并将其序列化为JSON。示例代码:

    var message = new Microsoft.Azure.ServiceBus.Message
    {
        MessageId = "0c8dfad9-6f0f-4d7f-a248-2a48fc899486",
        CorrelationId = "78b507b0-6266-458d-afe6-7882c935e481",
        Body = Encoding.UTF8.GetBytes("Hello world"),
    };

    var json = JsonConvert.SerializeObject(message);

但是,序列化时出现以下异常:

    Newtonsoft.Json.JsonSerializationException : 
Error getting value from 'ExpiresAtUtc' on 'Microsoft.Azure.ServiceBus.Message'.
    ---- System.InvalidOperationException : Operation is not valid due to the current state of the object.

如何创建有效消息(可以在以后序列化)的任何想法? ExpiresAtUtc只是因此无法直接设置。有没有办法间接设置它?

1 个答案:

答案 0 :(得分:2)

ExpiresAtUtc由代理设置,被视为内部(SystemProperties集合),并且是有意设计的。关于测试有一个similar question,如果你真的需要这个,那么实现它的唯一方法就是使用反射。

var message = new Message();
//message.TimeToLive = TimeSpan.FromSeconds(10);
var systemProperties = new Message.SystemPropertiesCollection();

// systemProperties.EnqueuedTimeUtc = DateTime.UtcNow.AddMinutes(1);
var bindings = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.SetProperty;
var value = DateTime.UtcNow.AddMinutes(1);
systemProperties.GetType().InvokeMember("EnqueuedTimeUtc", bindings, Type.DefaultBinder, systemProperties, new object[] { value});
// workaround "ThrowIfNotReceived" by setting "SequenceNumber" value
systemProperties.GetType().InvokeMember("SequenceNumber", bindings, Type.DefaultBinder, systemProperties, new object[] { 1 });

// message.systemProperties = systemProperties;
bindings = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.SetProperty;
message.GetType().InvokeMember("SystemProperties", bindings,Type.DefaultBinder, message, new object[] { systemProperties });

注意这种方法不是来自Azure Service Bus团队,因为他们认为这可能会导致您的生产过程中出现危险的做法。