【发布时间】：2014-03-12 01:47:22
【问题描述】：
在我的解决方案中，我有三个项目。一个是 WCF 服务，另一个是 Winforms 应用程序，我从中调用 Web 服务，最后一个是一个类库，其中的类已设计扩展了 soap 扩展类。
我的目标是在我从 Winforms 应用程序调用 WCF 服务时捕获响应和请求 xml。我在尝试捕获 xml 时遇到对象引用未设置错误。
这是我的类库源代码。
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.IO;
using System.Net;
using System.Xml;
namespace SoapLogger
{
public class TraceExtension : SoapExtension
{
private Stream oldStream;
private Stream newStream;
private static XmlDocument xmlRequest;
/// <summary>
/// Gets the outgoing XML request sent to PayPal
/// </summary>
public static XmlDocument XmlRequest
{
get { return xmlRequest; }
}
private static XmlDocument xmlResponse;
/// <summary>
/// Gets the incoming XML response sent from PayPal
/// </summary>
public static XmlDocument XmlResponse
{
get { return xmlResponse; }
}
/// <summary>
/// Save the Stream representing the SOAP request
/// or SOAP response into a local memory buffer.
/// </summary>
/// <param name="stream">
/// <returns></returns>
public override Stream ChainStream(Stream stream)
{
oldStream = stream;
newStream = new MemoryStream();
return newStream;
}
/// <summary>
/// If the SoapMessageStage is such that the SoapRequest or
/// SoapResponse is still in the SOAP format to be sent or received,
/// save it to the xmlRequest or xmlResponse property.
/// </summary>
/// <param name="message">
public override void ProcessMessage(SoapMessage message)
{
switch (message.Stage)
{
case SoapMessageStage.BeforeSerialize:
break;
case SoapMessageStage.AfterSerialize:
xmlRequest = GetSoapEnvelope(newStream);
CopyStream(newStream, oldStream);
break;
case SoapMessageStage.BeforeDeserialize:
CopyStream(oldStream, newStream);
xmlResponse = GetSoapEnvelope(newStream);
break;
case SoapMessageStage.AfterDeserialize:
break;
}
}
/// <summary>
/// Returns the XML representation of the Soap Envelope in the supplied stream.
/// Resets the position of stream to zero.
/// </summary>
/// <param name="stream">
/// <returns></returns>
private XmlDocument GetSoapEnvelope(Stream stream)
{
XmlDocument xml = new XmlDocument();
stream.Position = 0;
StreamReader reader = new StreamReader(stream);
xml.LoadXml(reader.ReadToEnd());
stream.Position = 0;
return xml;
}
/// <summary>
/// Copies a stream.
/// </summary>
/// <param name="from">
/// <param name="to">
private void CopyStream(Stream from, Stream to)
{
TextReader reader = new StreamReader(from);
TextWriter writer = new StreamWriter(to);
writer.WriteLine(reader.ReadToEnd());
writer.Flush();
}
#region NoOp
/// <summary>
/// Included only because it must be implemented.
/// </summary>
/// <param name="methodInfo">
/// <param name="attribute">
/// <returns></returns>
public override object GetInitializer(LogicalMethodInfo methodInfo,
SoapExtensionAttribute attribute)
{
return null;
}
/// <summary>
/// Included only because it must be implemented.
/// </summary>
/// <param name="WebServiceType">
/// <returns></returns>
public override object GetInitializer(Type WebServiceType)
{
return null;
}
/// <summary>
/// Included only because it must be implemented.
/// </summary>
/// <param name="initializer">
public override void Initialize(object initializer)
{
}
#endregion NoOp
}
这是我从 Winforms 应用程序调用 Web 服务的方式：
private void button1_Click(object sender, EventArgs e)
{
using (ServiceRef.TestServiceSoapClient oService = new ServiceRef.TestServiceSoapClient())
{
textBox1.Text = oService.HelloWorld("Sudip");
var soapRequest = SoapLogger.TraceExtension.XmlRequest.InnerXml;
var soapResponse = SoapLogger.TraceExtension.XmlResponse.InnerXml;
}
}
这两行导致对象引用错误
var soapRequest = SoapLogger.TraceExtension.XmlRequest.InnerXml;
var soapResponse = SoapLogger.TraceExtension.XmlResponse.InnerXml;
我就是不知道为什么会出错。
Winforms 应用程序有一个app.config，我在其中注册了我的类库程序集以捕获 xml。这是我的app.config 详细信息
<?xml version="1.0"?>
<configuration>
<system.serviceModel>
<bindings>
<basicHttpBinding>
<binding name="TestServiceSoap"/> </basicHttpBinding>
</bindings> <client> <endpoint address="http://localhost:6804/Service1.asmx"
binding="basicHttpBinding" bindingConfiguration="TestServiceSoap"
contract="ServiceRef.TestServiceSoap" name="TestServiceSoap"/>
</client>
</system.serviceModel>
<system.web>
<compilation debug="true" targetFramework="4.0" />
<webServices> <soapExtensionTypes>
<add type="SoapLogger.TraceExtension,SoapLogger" priority="1" group="0" />
</soapExtensionTypes> </webServices>
</system.web>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
</startup> </configuration>
当我搜索谷歌只是为了知道如何捕获请求/响应 xml 时，我得到了很多这样的文章。我关注了很多，但没有任何效果。
我为完成工作而关注的这个网址http://jramirezdev.net/blog/c-tip-capturar-los-mensajes-soap-de-un-servicio-asmx-que-hemos-referenciado
我不清楚是什么错误。我在类库方法中的每个方法处都设置了断点，但是当 Web 服务调用时，类库中没有执行任何方法。我不想使用任何像wireshark、fiddler这样的工具来捕获请求/响应xml，而是想以编程方式做同样的事情。
所以请指导我我的错误是什么？为什么我得到对象引用未设置错误？请查看我的代码或转到 url 链接并告诉我我的方法有什么问题
【问题讨论】：
标签： c# xml wcf web-services