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问题描述：<br/><br/>在用非.NET客户端调用WebService中，按照使用Soap Toolkit中的指导实现起来很简单，但在实际使用过程中却发现一个问题。<br/>假如Webservice提供的方法是：int SimpleMath.Add(int n1,int n2)，返回值是n1+n2, 但按照soap toolkit提供的例子，使用VC进行调用，得到的返回值却是0。<br/><br/>记录下我的解决过程，备忘。<br/><br/>试验环境：<br/>OS:WindowsXP Professional<br/>WebService：VS.NET 2003<br/>WebService运行环境：IIS<br/>客户端：VC6.0，VS.NET中的VC<br/>SoapToolkit SDK：3.0<br/><br/>问题再现：<br/>看Toolkit中稍微修改一下之后的例子代码：<br/><br/>#include <stdio.h><br/>#import "msxml4.dll" <br/>using namespace MSXML2;<br/>#import "C:\\Program Files\\Common Files\\MSSoap\\Binaries\\mssoap30.dll" exclude("IStream", "IErrorInfo", "ISequentialStream", "_LARGE_INTEGER", "_ULARGE_INTEGER", "tagSTATSTG", "_FILETIME")<br/>using namespace MSSOAPLib30;<br/><br/>int test2()<br/>{<br/><br/> ISoapSerializerPtr Serializer;<br/> ISoapReaderPtr Reader;<br/> ISoapConnectorPtr Connector;<br/> <br/> // Connect to the service<br/> Connector.CreateInstance(__uuidof(HttpConnector));<br/> <br/><br/> Connector->Property["EndPointURL"] = "<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://localhost/WSTest/SimpleMath.asmx?WSDL">  http://localhost/WSTest/SimpleMath.asmx?WSDL"<;/a>;;<br/> Connector->Connect();<br/> <br/> // Begin message<br/> Connector->Property["SoapAction"] = "<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/Add">http://tempuri.org/Add"<;/a>;;<br/> Connector->BeginMessage();<br/> <br/> // Create the SoapSerializer<br/> Serializer.CreateInstance(__uuidof(SoapSerializer));<br/> <br/> // Connect the serializer to the input stream of the connector<br/> Serializer->Init(_variant_t((IUnknown*)Connector->InputStream));<br/> <br/> // Build the SOAP Message<br/> Serializer->startEnvelope("","","");<br/> Serializer->startBody("");<br/> Serializer->startElement("Add","<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/">http://tempuri.org/"<;/a>;,"","");<br/> Serializer->startElement("n1","","","");<br/> Serializer->writeString("5");<br/> Serializer->endElement();<br/> Serializer->startElement("n2","","","");<br/> Serializer->writeString("10");<br/> Serializer->endElement();<br/> Serializer->endElement();<br/> Serializer->endBody();<br/> Serializer->endEnvelope();<br/> <br/> // Send the message to the web service<br/> Connector->EndMessage(); <br/> <br/> // Let us read the response<br/> Reader.CreateInstance(__uuidof(SoapReader));<br/> <br/> // Connect the reader to the output stream of the connector<br/> Reader->Load(_variant_t((IUnknown*)Connector->OutputStream), "");<br/> <br/> // Display the result<br/> printf("Answer: %s\\n", (const char*)Reader->RPCResult->text);<br/> return 0;<br/>}<br/><br/><br/>返回结果应该是15，但实际却返回了0。<br/>在网上搜索发现有人提议把WebService的方法的参数改为string，然后在方法内部转换，我觉得这不是一个好办法。事实上，我经过发现，这样的实现问题会更多。<br/><br/>返回结果应该是15，但实际却返回了0。<br/>在网上搜索发现有人提议把WebService的方法的参数改为string，然后在方法内部转换，我觉得这不是一个好办法。事实上，我经过发现，这样的实现问题会更多。<br/>分析过程：<br/><br/>用soap toolkit的跟踪工具MSSoapT看一下，客户端到底向WebService发送了什么数据：<br/><br/><SOAP-ENV:Envelope SOAP-ENV:encodingStyle="" xmlns:SOAP-ENV="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://schemas.xmlsoap.org/soap/envelope/">http://schemas.xmlsoap.org/soap/envelope/"<;/a>;><br/> <SOAP-ENV:Body SOAP-ENV:encodingStyle=""><br/> <SOAPSDK1:Add xmlns:SOAPSDK1="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/">http://tempuri.org/"<;/a>; SOAP-ENV:encodingStyle=""><br/> <n1 SOAP-ENV:encodingStyle="">5</n1> <br/> <n2 SOAP-ENV:encodingStyle="">10</n2> <br/> </SOAPSDK1:Add><br/> </SOAP-ENV:Body><br/> </SOAP-ENV:Envelope><br/><br/>再看看vs.NET调试中，IE浏览器发出的数据（模板）：<br/><br/><br/><?xml version="1.0" encoding="utf-8"?><br/><soap:Envelope xmlns:xsi="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://www.w3.org/2001/XMLSchema-instance">http://www.w3.org/2001/XMLSchema-instance"<;/a>; xmlns:xsd="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://www.w3.org/2001/XMLSchema">http://www.w3.org/2001/XMLSchema"<;/a>; xmlns:soap="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://schemas.xmlsoap.org/soap/envelope/">http://schemas.xmlsoap.org/soap/envelope/"<;/a>;><br/> <soap:Body><br/> <Add xmlns="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/">http://tempuri.org/"<;/a>;><br/> <n1>int</n1><br/> <n2>int</n2><br/> </Add><br/> </soap:Body><br/></soap:Envelope><br/><br/>区别在哪里？soaptoolkit的数据中，多了个encodingStyle属性，尽管没有制定值。我们想办法屏蔽这个属性。<br/>在SoapSerializer30的startElement方法中的参数中按照如下方式调用，可以不制定这个属性。<br/>改代码如下：<br/><br/><br/>...<br/> Serializer->startElement("Add","<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/">http://tempuri.org/"<;/a>;,"NONE","");<br/> Serializer->startElement("n1","","NONE","");<br/> Serializer->writeString("5");<br/> Serializer->endElement();<br/> Serializer->startElement("n2","","NONE","");<br/> Serializer->writeString("10");<br/> Serializer->endElement();<br/> Serializer->endElement();<br/>...<br/><br/><br/>但返回结果还是0，看来和encodingStyle无关。看看跟踪情况：<br/><br/><br/><SOAP-ENV:Envelope SOAP-ENV:encodingStyle="" xmlns:SOAP-ENV="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://schemas.xmlsoap.org/soap/envelope/">http://schemas.xmlsoap.org/soap/envelope/"<;/a>;><br/> <SOAP-ENV:Body SOAP-ENV:encodingStyle=""><br/> <SOAPSDK1:Add xmlns:SOAPSDK1="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/">http://tempuri.org/"<;/a>;><br/> <n1>5</n1> <br/> <n2>10</n2> <br/> </SOAPSDK1:Add><br/> </SOAP-ENV:Body><br/> </SOAP-ENV:Envelope><br/><br/>问题解决：<br/>比较一下vs.net中发出的请求，差别在哪里？认真看一下，n1和n2没有指定命名空间，那么就指定一下吧。<br/>把代码改成：<br/><br/><br/> Serializer->startElement("Add","<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/">http://tempuri.org/"<;/a>;,"NONE","");<br/> Serializer->startElement("n1","<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/">http://tempuri.org/"<;/a>;,"NONE","");<br/> Serializer->writeString("5");<br/> Serializer->endElement();<br/> Serializer->startElement("n2","<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/">http://tempuri.org/"<;/a>;,"NONE","");<br/> Serializer->writeString("10");<br/> Serializer->endElement();<br/> Serializer->endElement();<br/><br/>测试结果正常了，返回15。<br/><br/>看看这时候发出的xml数据：<br/><SOAP-ENV:Envelope SOAP-ENV:encodingStyle="" xmlns:SOAP-ENV="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://schemas.xmlsoap.org/soap/envelope/">http://schemas.xmlsoap.org/soap/envelope/"<;/a>;><br/> <SOAP-ENV:Body SOAP-ENV:encodingStyle=""><br/> <SOAPSDK1:Add xmlns:SOAPSDK1="<img align=absmiddle src=/sys_images/FileIcon/url.gif border='0'><a TARGET='_blank' href=http://tempuri.org/">http://tempuri.org/"<;/a>;><br/> <SOAPSDK1:n1>5</SOAPSDK1:n1> <br/> <SOAPSDK1:n2>10</SOAPSDK1:n2> <br/> </SOAPSDK1:Add><br/> </SOAP-ENV:Body><br/> </SOAP-ENV:Envelope><br/><br/>原因：<br/><br/>我也无法总结到底是谁的问题：（<br/><br/>也许是VS.NET的问题，也许是SoapToolKit的问题，也许是他提供的例子自身就有问题，也许是我的运行环境有问题，当然，更也许是我还没有真正理解xml的命名空间或没有正确使用WebService。
(iwgh) |