How do I get the XML SOAP request of an WCF Web service request?

I think you meant that you want to see the XML at the client, not trace it at the server. In that case, your answer is in the question I linked above, and also at How to Inspect or Modify Messages on the Client. But, since the .NET 4 version of that article is missing its C#, and the .NET 3.5 example has some confusion (if not a bug) in it, here it is expanded for your purpose.

You can intercept the message before it goes out using an IClientMessageInspector:

using System.ServiceModel.Dispatcher;public class MyMessageInspector : IClientMessageInspector{ }

The methods in that interface, BeforeSendRequest and AfterReceiveReply, give you access to the request and reply. To use the inspector, you need to add it to an IEndpointBehavior:

using System.ServiceModel.Description;public class InspectorBehavior : IEndpointBehavior{    public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)    {        clientRuntime.MessageInspectors.Add(new MyMessageInspector());    }}

You can leave the other methods of that interface as empty implementations, unless you want to use their functionality, too. Read the how-to for more details.

After you instantiate the client, add the behavior to the endpoint. Using default names from the sample WCF project:

ServiceReference1.Service1Client client = new ServiceReference1.Service1Client();client.Endpoint.Behaviors.Add(new InspectorBehavior());client.GetData(123);

Set a breakpoint in MyMessageInspector.BeforeSendRequest(); request.ToString() is overloaded to show the XML.

If you are going to manipulate the messages at all, you have to work on a copy of the message. See Using the Message Class for details.

Thanks to Zach Bonham's answer at another question for finding these links.

Option 1

Use message tracing/logging.

Have a look here and here.

Option 2

You can always use Fiddler to see the HTTP requests and response.

Option 3

Use System.Net tracing.

OperationContext.Current.RequestContext.RequestMessage 

this context is accesible server side during processing of request.This doesn`t works for one-way operations