首页 > 解决方案 > Rebus Pub Sub:检索订阅者的标头

问题描述

标头与 Azure 服务总线一起发布,如下所示:

 string content = "body";
 await _busPublisher.Activator.Bus.Publish(content, headers);

如何检索订阅者的标题和内容?

class Handler :  IHandleMessages<string>
    {

    public Handler(IMessageContext messageContext, ILog log)
    {
        _messageContext = messageContext;
        _log = log;
    }

        public async Task Handle(string message)
        {
            Console.WriteLine("Handle(string message): {0}", message);

        }
    }

更新

以下是一种解决方案。这是最好的解决方案吗?

        public Handler(IMessageContext messageContext, ILog log)
    {
        _messageContext = messageContext;
        _log = log;
    }
            public async Task Handle(string message)
            {
                Console.WriteLine("Handle(string message): {0} ", message);
                Console.WriteLine("headers: {0} ", string.Join(' ', _messageContext.Headers));

            }

当像下面这样实例化 Handler 时,是否可以使用依赖注入来代替?

        var Activator = new BuiltinHandlerActivator();

        Activator.Register((mc) =>
            {
                return new Handler(mc, log);  //no new?

            }

标签: rebusrebus-azureservicebus

解决方案


接受IMessageContext注入处理程序的构造函数是要走的路:

public class Handler : IHandleMessages<string>
{
    readonly IMessageContext messageContext;

    public Handler(IMessageContext messageContext, ILog log)
    {
        this.messageContext = messageContext;
    }

    public async Task Handle(string message)
    {
        var headers = messageContext.Headers;

        // do stuff
    }
}

如果你正在使用BuiltinHandlerActivator,你可以像这样注入它:

activator.Register(context => new Handler(context));

或者,如果您还需要IBus在您的处理程序中:

activator.Register((bus, context) => new Handler(bus, context));

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