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WCF and Silverlight - How to add custom information to a message header

In acest post am discutat despre cum se pot pune informatii in header-ul unui mesaj care este trimis prin WCF. In cazul in care incercati sa folositi aceasta solutie pentru un client pe Silverlight, o sa observati ca desi serverul adauga proprietatiile in header-ul mesajului acestea nu ajung la client, chiar daca pe sarma sunt adaugate.
Din Silverlight nu avem acces la toate proprietatiile care sunt trimise in header. Avem acces doar la cateva proprietati. De exemplu una din propietati este StatusCode. Acesta are valoarea 200 daca apelul s-a terminat cu success.
Datele care le punem in header pentru un client Siverlight, trebuie sa fie puse ca un nou Header. Mai jos gasiti cum puteti adauga un nou header de pe server, iar clientul cum il poate accesa. Al doilea parametru pe care l-am setat cu empty string reprezinta namespace URI pentru header-ul nostru.
public class ServerTokenInspector : IDispatchMessageInspector
{
public void BeforeSendReply(ref Message reply, object correlationState)
{
reply.Headers.Add(MessageHeader.CreateHeader("ServerToken", string.Empty, Guid.NewGuid()));
}

public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
{
return null;
}
}

public class ServerTokenClientInspector : IClientMessageInspector
{
public void AfterReceiveReply(ref Message reply, object correlationState)
{
if (reply.Headers.FindHeader("ServerToken", string.Empty) >= 0)
{
Guid token = reply.Headers.GetHeader<Guid>("ServerToken", string.Empty);
}
}

public object BeforeSendRequest(ref Message request, IClientChannel channel)
{
return null;
}
}

Enjoy!

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