Classe SoapExtension

using System;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.IO;
using System.Net;

	// Define a SOAP Extension that traces the SOAP request and SOAP
	// response for the XML Web service method the SOAP extension is
	// applied to.

	public class TraceExtension : SoapExtension 
	{
		Stream oldStream;
		Stream newStream;
		string filename;

		// Save the Stream representing the SOAP request or SOAP response into
		// a local memory buffer.
		public override Stream ChainStream( Stream stream )
		{
			oldStream = stream;
			newStream = new MemoryStream();
			return newStream;
		}

		// When the SOAP extension is accessed for the first time, the XML Web
		// service method it is applied to is accessed to store the file
		// name passed in, using the corresponding SoapExtensionAttribute.	
		public override object GetInitializer(LogicalMethodInfo methodInfo, SoapExtensionAttribute attribute) 
		{
			return ((TraceExtensionAttribute) attribute).Filename;
		}

		// The SOAP extension was configured to run using a configuration file
		// instead of an attribute applied to a specific XML Web service
		// method.
		public override object GetInitializer(Type WebServiceType) 
		{
			// Return a file name to log the trace information to, based on the
			// type.
			return "C:\\" + WebServiceType.FullName + ".log";    
		}

		// Receive the file name stored by GetInitializer and store it in a
		// member variable for this specific instance.
		public override void Initialize(object initializer) 
		{
			filename = (string) initializer;
		}

		//  If the SoapMessageStage is such that the SoapRequest or
		//  SoapResponse is still in the SOAP format to be sent or received,
		//  save it out to a file.
		public override void ProcessMessage(SoapMessage message) 
		{
			switch (message.Stage) 
			{
				case SoapMessageStage.BeforeSerialize:
					break;
				case SoapMessageStage.AfterSerialize:
					WriteOutput(message);
					break;
				case SoapMessageStage.BeforeDeserialize:
					WriteInput(message);
					break;
				case SoapMessageStage.AfterDeserialize:
					break;
			}
		}

		public void WriteOutput(SoapMessage message)
		{
			newStream.Position = 0;
			FileStream fs = new FileStream(filename, FileMode.Append,
				FileAccess.Write);
			StreamWriter w = new StreamWriter(fs);

			string soapString = (message is SoapServerMessage) ? "SoapResponse" : "SoapRequest";
			w.WriteLine("-----" + soapString + " at " + DateTime.Now);
			w.Flush();
			Copy(newStream, fs);
			w.Close();
			newStream.Position = 0;
			Copy(newStream, oldStream);
		}

		public void WriteInput(SoapMessage message)
		{
			Copy(oldStream, newStream);
			FileStream fs = new FileStream(filename, FileMode.Append,
				FileAccess.Write);
			StreamWriter w = new StreamWriter(fs);

			string soapString = (message is SoapServerMessage) ?
				"SoapRequest" : "SoapResponse";
			w.WriteLine("-----" + soapString + 
				" at " + DateTime.Now);
			w.Flush();
			newStream.Position = 0;
			Copy(newStream, fs);
			w.Close();
			newStream.Position = 0;
		}

		void Copy(Stream from, Stream to) 
		{
			TextReader reader = new StreamReader(from);
			TextWriter writer = new StreamWriter(to);
			writer.WriteLine(reader.ReadToEnd());
			writer.Flush();
		}
	}

	// Create a SoapExtensionAttribute for the SOAP Extension that can be
	// applied to an XML Web service method.
	[AttributeUsage(AttributeTargets.Method)]
	public class TraceExtensionAttribute : SoapExtensionAttribute 
	{

		private string filename = "c:\\log.txt";
		private int priority;

		public override Type ExtensionType 
		{
			get { return typeof(TraceExtension); }
		}

		public override int Priority 
		{
			get { return priority; }
			set { priority = value; }
		}

		public string Filename 
		{
			get 
			{
				return filename;
			}
			set 
			{
				filename = value;
			}
		}
	}