BeforeSendRequest question

Question

Hi Everyone -

I am trying to perform some modifications to the message in the BeforeSendRequest event.  What would be good is if I could just load the message into an XmlDocument, perform the changes that I need, and then update the message that is passed in by ref.

I can load the XmlDocument; however, I don't see a clear way to use to get that to update the message reference that is passed into the method.

Is this possible?  Is there a better way to do this?

Thanks.
Ken

Answer 1

You can definitely do that, just open the XmlDocument as a reader, and create a new message from it. The example below shows how this can be done:

    public class Post_f01a7120_0351_4be2_b45f_b7fb382c8a1f
    {
        [ServiceContract]
        public interface ITest
        {
            [OperationContract]
            string Echo(string input);
        }
        [ServiceBehavior(IncludeExceptionDetailInFaults = true)]
        public class Service : ITest
        {
            public string Echo(string input)
            {
                return input;
            }
        }
        public class MyInspector : IDispatchMessageInspector, IEndpointBehavior
        {
            public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
            {
                return null;
            }
            public void BeforeSendReply(ref Message reply, object correlationState)
            {
                MemoryStream ms = new MemoryStream();
                XmlDictionaryWriter writer = XmlDictionaryWriter.CreateTextWriter(ms);
                reply.WriteMessage(writer);
                writer.Flush();
                ms.Position = 0;
                XmlDocument doc = new XmlDocument();
                doc.Load(ms);

                // change XmlDocument
                XmlNamespaceManager nsManager = new XmlNamespaceManager(doc.NameTable);
                nsManager.AddNamespace("s", "http://schemas.xmlsoap.org/soap/envelope/");
                nsManager.AddNamespace("tempuri", "http://tempuri.org/");
                XmlNode node = doc.SelectSingleNode("/s:Envelope/s:Body/tempuri:EchoResponse/tempuri:EchoResult", nsManager);
                if (node != null)
                {
                    node.InnerText = node.InnerText + " - modified";
                }

                ms = new MemoryStream();
                writer = XmlDictionaryWriter.CreateTextWriter(ms);
                doc.WriteTo(writer);
                writer.Flush();
                ms.Position = 0;
                XmlDictionaryReader reader = XmlDictionaryReader.CreateTextReader(ms, XmlDictionaryReaderQuotas.Max);
                Message newReply = Message.CreateMessage(reader, int.MaxValue, reply.Version);
                reply = newReply;
            }
            public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters) { }

            public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime) { }

            public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
            {
                endpointDispatcher.DispatchRuntime.MessageInspectors.Add(this);
            }
            public void Validate(ServiceEndpoint endpoint) { }
        }
        public static void Test()
        {
            string baseAddress = "http://" + Environment.MachineName + ":8000/Service";
            ServiceHost host = new ServiceHost(typeof(Service), new Uri(baseAddress));
            ServiceEndpoint endpoint = host.AddServiceEndpoint(typeof(ITest), new BasicHttpBinding(), "");
            endpoint.Behaviors.Add(new MyInspector());
            host.Open();
            Console.WriteLine("Host opened");

            ChannelFactory<ITest> factory = new ChannelFactory<ITest>(new BasicHttpBinding(), new EndpointAddress(baseAddress));
            ITest proxy = factory.CreateChannel();
            Console.WriteLine(proxy.Echo("Hello world"));
            ((IClientChannel)proxy).Close();
            factory.Close();

            Console.WriteLine("Press ENTER to close");
            Console.ReadLine();
            host.Close();
        }
    }

Answer 2

That is exactly what I needed.  Thanks!

Answer 3

I am trying to do the same thing with the IClientMessageInspector.  I have looked around online and found examples but I can't seem to get this down.  I also need to add message level security through .NET code.  The service requires that I provide UserNameToken credentials.  I have been working on this for about 3-4 days now and I am running out of time.  Any help would be greatly appreciated.