C# 利用Http Get，Post，Soap调用WebService

原文地址：http://www.cnblogs.com/Fooo/p/5507153.html
http://blog.youkuaiyun.com/chlyzone/article/details/8210718
该方法是是最为灵活的方法。

using System;
using System.Collections;
using System.IO;
using System.Net;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
namespace Bingosoft.RIA.Common
{
    /// <summary>
    ///  利用WebRequest/WebResponse进行WebService调用的类
    /// </summary>
    public class WebServiceCaller
    {
        #region Tip:使用说明
        //webServices 应该支持Get和Post调用，在web.config应该增加以下代码
        //<webServices>
        //  <protocols>
        //    <add name="HttpGet"/>
        //    <add name="HttpPost"/>
        //  </protocols>
        //</webServices>

        //调用示例：
        //Hashtable ht = new Hashtable();  //Hashtable 为webservice所需要的参数集
        //ht.Add("str", "test");
        //ht.Add("b", "true");
        //XmlDocument xx = WebSvcCaller.QuerySoapWebService("http://localhost:81/service.asmx", "HelloWorld", ht);
        //MessageBox.Show(xx.OuterXml);
        #endregion

        /// <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, String MethodName, 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, String MethodName, Hashtable Pars)
        {
            if (_xmlNamespaces.ContainsKey(URL))
            {
                return QuerySoapWebService(URL, MethodName, Pars, _xmlNamespaces[URL].ToString());
            }
            else
            {
                return QuerySoapWebService(URL, MethodName, Pars, GetNamespace(URL));
            }
        }

        private static XmlDocument QuerySoapWebService(String URL, String MethodName, 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", "http://schemas.xmlsoap.org/soap/envelope/");
            XmlElement soapBody = doc.CreateElement("soap", "Body", "http://schemas.xmlsoap.org/soap/envelope/");
            //XmlElement soapMethod = doc.createElement_x_x(MethodName);
            XmlElement soapMethod = doc.CreateElement(MethodName);
            soapMethod.SetAttribute("xmlns", XmlNs);
            foreach (string k in Pars.Keys)
            {
                //XmlElement soapPar = doc.createElement_x_x(k);
                XmlElement soapPar = doc.CreateElement(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();
            }
        }

        /// <summary>
        /// 设置凭证与超时时间
        /// </summary>
        /// <param name="request"></param>
        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, 0, 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);
        }

        private static Hashtable _xmlNamespaces = new Hashtable();//缓存xmlNamespace，避免重复调用GetNamespace
    }
}

soap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);

这个类有三个公用的方法：QuerySoapWebService为通用的采用Soap方式调用WebService，QueryGetWebService采用GET方式调用，QueryPostWebService采用POST方式调用，后两个方法需要WebService服务器支持相应的调用方式。三个方法的参数和返回值相同：URL为Webservice的Url地址(以.asmx结尾的)；MethodName为要调用的方法名称；Pars为参数表，它的Key为参数名称，Value为要传递的参数的值,Value可为任意对象，前提是这个对象可以被xml序列化。注意方法名称、参数名称、参数个数必须完全匹配才能正确调用。第一次以Soap方式调用时，因为需要查询WSDL获取xmlns，因此需要时间相对长些，第二次调用不用再读WSDL，直接从缓存读取。这三个方法的返回值均为XmlDocument对象，这个返回的对象可以进行各种灵活的操作。最常用的一个SelectSingleNode方法，可以让你一步定位到Xml的任何节点，再读取它的文本或属性。也可以直接调用Save保存到磁盘。采用Soap方式调用时，根结点名称固定为root。
这个类主要是利用了WebRequest/WebResponse来完成各种网络查询操作。为了精简明了，这个类中没有添加错误处理，需要在调用的地方设置异常捕获。
下面是一个调用实例：
protected void Page_Load(object sender , EventArgs e)
…{
try
…{
Hashtable pars = new Hashtable();
String Url = “http://www.260dns.cn/Services/Weather.asmx“;
pars[“city”] = “上海”;
pars[“wdate”]=”2008-3-19”;
XmlDocument doc = WebSvcCaller.QuerySoapWebService(Url , “GetWeather” , pars);
Response.Write(doc.OuterXml);
}
catch (Exception ex)
…{
Response.Write(ex.Message);
}
}