用asp.net2 開發SoapExtension所出現的問題

鬱悶 ！！最近在學習ＳｏａｐＥｘｔｅｎｓｉｏｎ的開發，但是發現我web service代碼不會調用我編寫的ＴｒａｃｅＥｘｔｅｎｓｉｏｎ這個Soap擴展，不知道是什麼原因造成的，還請各位高手在此多多指點一二。在此先謝過了。。。

下面這段代碼就是Ｓｏａｐ擴展，我寫成了ＤＬＬ來調用。

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

namespace TraceExtension
{
    // 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;
                default:
                    throw new Exception("invalid stage");
            }
        }

        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;
            }
        }
    }


}

以下是我的web service頁面，不知爲何就是不調用日誌功能.

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



/// <summary>
/// WebService 的摘要說明
/// </summary>
[WebService(Namespace = "http://www.lanbridge.net/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class WebService : System.Web.Services.WebService {

    public WebService () {

        //如果使用設計的組件，請取消註釋以下行 
        //InitializeComponent(); 
       
    }

    [WebMethod]
    [TraceExtension.TraceExtension(Filename = "C:/data.xml",Priority=1)]
    public string HelloWorld(string v) {                
        return v+"asdf";
    }
    

}

在web.config中我做了以下配置：

　<webServices>
      <soapExtensionTypes>        
        <add type="TraceExtension.TraceExtension,TraceExtension" priority="1"  group="High"  />
      </soapExtensionTypes>
    </webServices>