前言

使用 C#以B/S方式构建WebService服务十分简便，即是使用Asp.net在网站中添加WebService服务并使用IIS发布。但如需要在C/S程序中发布WebService服务则没有直接可用的类库。因此需要使用另外的方式实现WebService服务。

一、实现思路

WebService实际是使用Http并遵循SOAP协议格式进行交互。能够进行Http通讯即可实现WebService服务，只是没了现成的类库就需要自己编写解析SOAP格式数据包和组织应答包。

二、步骤

1.使用HttpListener构建服务

代码如下（示例）：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading;
using System.Net;
using System.Web;

namespace LadarManufacturabilityTooling
{
    public class HttpServic
    {
        public delegate byte[] OnGetResponseDataHandle(HttpListenerPostValue Sender);
        public event OnGetResponseDataHandle OnGetResponse;

        private static HttpListener httpPostRequest = new HttpListener();
        private static bool IsRun = true;
        public HttpServic(IPAddress HttpServerIP, int HttpServerPort)
        {
            httpPostRequest.Prefixes.Add("http://" + HttpServerIP.ToString() + ":" + HttpServerPort.ToString() + "/");

            try
            { 
                httpPostRequest.Start();
            }
            catch(Exception ex)
            {
                string Mes = ex.Message;
            }

            Thread ThrednHttpPostRequest = new Thread(new ThreadStart(httpPostRequestHandle));
            ThrednHttpPostRequest.Start();
        }

        private void httpPostRequestHandle()
        {
            while (IsRun)
            {
                try
                { 
                    HttpListenerContext requestContext = httpPostRequest.GetContext();
                    Thread threadsub = new Thread(new ParameterizedThreadStart((requestcontext) =>
                    {
                        HttpListenerContext request = (HttpListenerContext)requestcontext;
                        //获取Post请求中的参数和值帮助类  
                        HttpListenerPostParaHelper httppost = new HttpListenerPostParaHelper(request);
                        //获取Post过来的参数和数据  
                        HttpListenerPostValue lst = httppost.GetHttpListenerPostValue();

                        byte[] buffer = null;
                        if (lst != null)
                        {
                            if(OnGetResponse != null)
                                buffer = OnGetResponse(lst);
                        }

                        if(buffer != null)
                        {//Response  
                            try
                            { 
                                request.Response.StatusCode = 200;
                                request.Response.Headers.Add("SOAPAction", "");
                                request.Response.Headers.Add("User-Agent", "gSOAP/2.8");
                                request.Response.ContentType = "text/xml; charset=utf-8";
                                request.Response.ContentEncoding = Encoding.UTF8;
                                request.Response.ContentLength64 = buffer.Length;
                                var output = request.Response.OutputStream;
                                output.Write(buffer, 0, buffer.Length);
                                output.Close();
                            }
                            catch(Exception ex2)
                            {
                            }
                        }
                        else
                        {
                            try
                            { 
                                request.Response.Close();
                            }
                            catch
                            { }
                        }
                    }));
                    threadsub.Start(requestContext);
                }
                catch (Exception ex)
                {
                    string Mes = ex.Message;
                }
            }
        }
        
        public void StopHttpThread()
        {
            IsRun = false;
            httpPostRequest.Abort();
        }
    }
}

启动服务后在httpPostRequestHandle()函数中编写对监听到的服务请求的处理。

//获取Post过来的参数和数据  
HttpListenerPostValue lst = httppost.GetHttpListenerPostValue();

GetHttpListenerPostValue();函数作用为取出请求中的数据部分和请求的名称。涉及到的类定义和代码如下：

/// <summary>  
    /// HttpListenner监听Post请求参数值实体  
    /// </summary>  
    public class HttpListenerPostValue
    {
        /// <summary>  
        /// 0=> 参数  
        /// 1=> 文件  
        /// </summary>  
        public int type = 0;
        /// <summary>
        /// 请求的类型名称
        /// </summary>
        public string name;
        /// <summary>
        /// 数据字符串
        /// </summary>
        public string datas;
    }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Net;
using System.Web;
using System.IO;

namespace LadarManufacturabilityTooling
{
    /// <summary>  
    /// 获取Post请求中的参数和值帮助类  
    /// </summary>  
    public class HttpListenerPostParaHelper
    {
        private HttpListenerContext request;

        public HttpListenerPostParaHelper(HttpListenerContext request)
        {
            this.request = request;
        }

        /// <summary>  
        /// 获取Post过来的参数和数据  
        /// </summary>  
        /// <returns></returns>  
        public HttpListenerPostValue GetHttpListenerPostValue()
        {
            try
            {
                HttpListenerPostValue HttpListenerPostValueList = new HttpListenerPostValue();
                if (true)
                {
                    Stream body = request.Request.InputStream;
                    Encoding encoding = Encoding.UTF8;
                    StreamReader reader = new System.IO.StreamReader(body, encoding);
                    if (request.Request.ContentType != null)
                    {
                        Console.WriteLine("Client data content type {0}", request.Request.ContentType);
                    }
                    string datas = reader.ReadToEnd();
                    string Requestname = request.Request.RawUrl.Replace("/","");
                    HttpListenerPostValueList.datas = datas;
                    HttpListenerPostValueList.name = Requestname;
                    Console.WriteLine(datas);
                }
                return HttpListenerPostValueList;
            }
            catch (Exception ex)
            {
                return null;
            }
        }
    }
}

以上部分和构建普通的http监听服务并无区别。

2.处理请求的数据

OnGetResponse事件用于处理请求的数据并组织回包
代码如下（示例）：

private byte[] ThisHttpServic_OnGetResponse(HttpListenerPostValue Sender)
        {
            byte[] buffer = null;
            string restr = "";
            //处理收到的请求
            switch (Sender.name)
            {
                case "MyServiceName":
                {
                    string xmlOrgstr = "";
                    int iStartPos = Sender.datas.IndexOf("<xmlData>", 1);
                    int iStopPos = Sender.datas.IndexOf("</xmlData>", 1);
                    if (iStartPos > 0)
                    {
                        xmlOrgstr = Sender.datas.Substring(iStartPos + 9, iStopPos - iStartPos - 9);
                    }
                    string xmlstr = HttpUtility.HtmlDecode(xmlOrgstr);
                    string LOGIN_ACK = GetPack(xmlstr);
                    restr = GetCompleteSoapString(System.Security.SecurityElement.Escape(LOGIN_ACK));
                    break;
                }
                default:
                    restr = "";
                    break;
            }

            buffer = System.Text.Encoding.UTF8.GetBytes(restr);
            return buffer;
        }

需要从收到的http请求的数据部分提取出WebService服务的参数。
收到的数据包原文（Sender.datas）为：

<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:client1="http://LSCService.chinamobile.com" xmlns:service1="http://FSUService.chinamobile.com"><SOAP-ENV:Body SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"><client1:invoke><xmlData>&lt;?xml version="1.0" encoding="UTF-8" ?&gt;&lt;Request&gt;&lt;PK_Type&gt;&lt;Name&gt;LOGIN&lt;/Name&gt;&lt;/PK_Type&gt;&lt;Info&gt;&lt;UserName&gt;cmcc&lt;/UserName&gt;&lt;PassWord&gt;B101341CC2E4D6F5B395C7544B96A826&lt;/PassWord&gt;&lt;FSUID&gt;21202110060001&lt;/FSUID&gt;&lt;FSUIP&gt;192.168.1.253&lt;/FSUIP&gt;&lt;FSUMAC&gt;00:21:92:01:b5:9f&lt;/FSUMAC&gt;&lt;FSUVER&gt;2.0.0.15 for CMCC&lt;/FSUVER&gt;&lt;/Info&gt;&lt;/Request&gt;&#xD;&#xA;</xmlData></client1:invoke></SOAP-ENV:Body></SOAP-ENV:Envelope>

作为示例的服务的参数名为xmlData从SOAP中截取出参数的字符串进行处理。
由于xmlData中的内容是一串xml字符，SOAP传输时经过了转义，因此还需要转义回来。

string xmlstr = HttpUtility.HtmlDecode(xmlOrgstr);

处理完相应的业务，将需要回复的数据加上SOAP协议的头尾组好回复包返回。需要转义的部分记得进行符号转义。

System.Security.SecurityElement.Escape(LOGIN_ACK)

SOAP协议的头尾根据WebService服务函数的定义有所不同，需要自行组织。示例如下：

        /// <summary>
        /// 返回完整的SOAP包
        /// </summary>
        /// <param name="XmlData">应答部分</param>
        /// <returns></returns>
        public static string GetCompleteSoapString(string XmlData)
        {
            string restr = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
            + "<SOAP-ENV:Envelope xmlns:SOAP-ENV=\"http://schemas.xmlsoap.org/soap/envelope/\""
            + " xmlns:SOAP-ENC=\"http://schemas.xmlsoap.org/soap/encoding/\""
            + " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""
            + " xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\""
            + " xmlns:client1=\"http://LService.mobile.com\""
            + " xmlns:service1=\"http://FService.mobile.com\">"
            + "<SOAP-ENV:Body>"
            + "<client1:invokeResponse><invokeReturn>";
            string restrEnd = "</invokeReturn></client1:invokeResponse></SOAP-ENV:Body></SOAP-ENV:Envelope>";
            restr = restr + XmlData + restrEnd;
            return restr;
        }