不记得在哪儿看的了，当时存下来了，现在贴出来，供参考。
?
using System;
using System.Web;
using System.Xml;
using System.Collections;
using System.Net;
using System.Text;
using System.IO;
using System.Xml.Serialization;
//By huangz 2008-3-19
/// <summary>
///??利用WebRequest/WebResponse进行WebService调用的类
/// </summary>
public class WebSvcCaller
{
????//<webServices>
????//??<protocols>
????//????<add name="HttpGet"/>
????//????<add name="HttpPost"/>
????//??</protocols>
????//</webServices>
????private static Hashtable _xmlNamespaces = new Hashtable();//缓存xmlNamespace，避免重复调用GetNamespace
???
????/// <summary>
????/// 需要WebService支持Post调用
????/// </summary>
????public static XmlDocument QueryPostWebService(String URL,String MethodName,Hashtable Pars)
????{
????????HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(URL + "/" + MethodName);
????????request.Method = "POST";
????????request.ContentType = "application/x-www-form-urlencoded";
????????SetWebRequest(request);
????????byte[] data = EncodePars(Pars);
????????WriteRequestData(request,data);
????????return ReadXmlResponse(request.GetResponse());
????}
???
????/// <summary>
????/// 需要WebService支持Get调用
????/// </summary>
????public static XmlDocument QueryGetWebService(String URL,Hashtable Pars)
????{
????????HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(URL + "/" + MethodName + "?" + ParsToString(Pars));
????????request.Method = "GET";
????????request.ContentType = "application/x-www-form-urlencoded";
????????SetWebRequest(request);
????????return ReadXmlResponse(request.GetResponse());
????}
???
????/// <summary>
????/// 通用WebService调用(Soap),参数Pars为String类型的参数名、参数值
????/// </summary>
????public static XmlDocument QuerySoapWebService(String URL,Hashtable Pars)
????{
????????if (_xmlNamespaces.ContainsKey(URL))
????????{
????????????return QuerySoapWebService(URL,MethodName,Pars,_xmlNamespaces[URL].ToString());
????????}
????????else
????????{
????????????return QuerySoapWebService(URL,GetNamespace(URL));
????????}
????}
????private static XmlDocument QuerySoapWebService(String URL,Hashtable Pars,string XmlNs)
????{????
????????_xmlNamespaces[URL] = XmlNs;//加入缓存，提高效率
????????HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(URL);
????????request.Method = "POST";
????????request.ContentType = "text/xml; charset=utf-8";
????????request.Headers.Add("SOAPAction",""" + XmlNs + (XmlNs.EndsWith("/") ? "" : "/") + MethodName + """);
????????SetWebRequest(request);
????????byte[] data = EncodeParsToSoap(Pars,XmlNs,MethodName);
????????WriteRequestData(request,data);
????????XmlDocument doc = new XmlDocument(),doc2 = new XmlDocument();
????????doc = ReadXmlResponse(request.GetResponse());
????????XmlNamespaceManager mgr = new XmlNamespaceManager(doc.NameTable);
????????mgr.AddNamespace("soap","http://schemas.xmlsoap.org/soap/envelope/");
????????String RetXml = doc.SelectSingleNode("//soap:Body/*/*",mgr).InnerXml;
????????doc2.LoadXml("<root>" + RetXml + "</root>");
????????AddDelaration(doc2);
????????return doc2;
????}
????private static string GetNamespace(String URL)
????{
????????HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URL + "?WSDL");
????????SetWebRequest(request);
????????WebResponse response = request.GetResponse();
????????StreamReader sr = new StreamReader(response.GetResponseStream(),Encoding.UTF8);
????????XmlDocument doc = new XmlDocument();
????????doc.LoadXml(sr.ReadToEnd());
????????sr.Close();
????????return doc.SelectSingleNode("//@targetNamespace").Value;
????}
????private static byte[] EncodeParsToSoap(Hashtable Pars,String XmlNs,String MethodName)
????{
????????XmlDocument doc = new XmlDocument();
????????doc.LoadXml("<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"></soap:Envelope>");
????????AddDelaration(doc);
????????XmlElement soapBody = doc.createElement_x_x("soap","Body",160)" rel="nofollow" target="_blank">http://schemas.xmlsoap.org/soap/envelope/");
????????XmlElement soapMethod = doc.createElement_x_x(MethodName);
????????soapMethod.SetAttribute("xmlns",XmlNs);
????????foreach (string k in Pars.Keys)
????????{
????????????XmlElement soapPar = doc.createElement_x_x(k);
????????????soapPar.InnerXml = ObjectToSoapXml(Pars[k]);
????????????soapMethod.AppendChild(soapPar);
????????}
????????soapBody.AppendChild(soapMethod);
????????doc.DocumentElement.AppendChild(soapBody);
????????return Encoding.UTF8.GetBytes(doc.OuterXml);
????}
????private static string ObjectToSoapXml(object o)
????{
????????XmlSerializer mySerializer = new XmlSerializer(o.GetType());
????????MemoryStream ms = new MemoryStream();
????????mySerializer.Serialize(ms,o);
????????XmlDocument doc = new XmlDocument();
????????doc.LoadXml(Encoding.UTF8.GetString(ms.ToArray()));
????????if (doc.DocumentElement != null)
????????{
????????????return doc.DocumentElement.InnerXml;
????????}
????????else
????????{
????????????return o.ToString();
????????}
????}
????private static void SetWebRequest(HttpWebRequest request)
????{
????????request.Credentials = CredentialCache.DefaultCredentials;
????????request.Timeout = 10000;
????}
????private static void WriteRequestData(HttpWebRequest request,byte[] data)
????{
????????request.ContentLength = data.Length;
????????Stream writer = request.GetRequestStream();
????????writer.Write(data,data.Length);
????????writer.Close();
????}
????private static byte[] EncodePars(Hashtable Pars)
????{
????????return Encoding.UTF8.GetBytes(ParsToString(Pars));
????}
????private static String ParsToString(Hashtable Pars)
????{
????????StringBuilder sb = new StringBuilder();
????????foreach (string k in Pars.Keys)
????????{
????????????if (sb.Length > 0)
????????????{
????????????????sb.Append("&");
????????????}
????????????//sb.Append(HttpUtility.UrlEncode(k) + "=" + HttpUtility.UrlEncode(Pars[k].ToString()));
????????}
????????return sb.ToString();
????}
????private static XmlDocument ReadXmlResponse(WebResponse response)
????{
????????StreamReader sr = new StreamReader(response.GetResponseStream(),Encoding.UTF8);
????????String retXml = sr.ReadToEnd();
????????sr.Close();
????????XmlDocument doc = new XmlDocument();
????????doc.LoadXml(retXml);
????????return doc;
????}
????private static void AddDelaration(XmlDocument doc)
????{
????????XmlDeclaration decl = doc.CreateXmlDeclaration("1.0","utf-8",null);
????????doc.InsertBefore(decl,doc.DocumentElement);
????}
}
调用示例：
Hashtable ht = new Hashtable();
ht.Add("str","test");
ht.Add("b","true");
XmlDocument xx = WebSvcCaller.QuerySoapWebService("http://localhost:81/service.asmx","HelloWorld",ht); MessageBox.Show(xx.OuterXml);
