How to add a custom HTTP header to every WCF call?

Question

I have a WCF service that is hosted in a Windows Service. Clients that using this service must pass an identifier every time they\'re calling service methods (because that i

Answer 1

This is what worked for me, adapted from Adding HTTP Headers to WCF Calls

// Message inspector used to add the User-Agent HTTP Header to the WCF calls for Server
public class AddUserAgentClientMessageInspector : IClientMessageInspector
{
    public object BeforeSendRequest(ref System.ServiceModel.Channels.Message request, IClientChannel channel)
    {
        HttpRequestMessageProperty property = new HttpRequestMessageProperty();

        var userAgent = "MyUserAgent/1.0.0.0";

        if (request.Properties.Count == 0 || request.Properties[HttpRequestMessageProperty.Name] == null)
        {
            var property = new HttpRequestMessageProperty();
            property.Headers["User-Agent"] = userAgent;
            request.Properties.Add(HttpRequestMessageProperty.Name, property);
        }
        else
        {
            ((HttpRequestMessageProperty)request.Properties[HttpRequestMessageProperty.Name]).Headers["User-Agent"] = userAgent;
        }
        return null;
    }

    public void AfterReceiveReply(ref System.ServiceModel.Channels.Message reply, object correlationState)
    {
    }
}

// Endpoint behavior used to add the User-Agent HTTP Header to WCF calls for Server
public class AddUserAgentEndpointBehavior : IEndpointBehavior
{
    public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)
    {
        clientRuntime.MessageInspectors.Add(new AddUserAgentClientMessageInspector());
    }

    public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
    {
    }

    public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
    {
    }

    public void Validate(ServiceEndpoint endpoint)
    {
    }
}

After declaring these classes you can add the new behavior to your WCF client like this:

client.Endpoint.Behaviors.Add(new AddUserAgentEndpointBehavior());