动态生成WebService代理类

　　使用wsdl生成的代理类或者添加web引用方式生成的WebReference文件夹，都得在对方WebService发布出来之后，才能产生对应的代理类。如果之后对方WebService中添加了新点方法，我们要调用的话，必须重新生成已经存在的代理类，更新起来，很麻烦。其实，在明确接口名称及参数，返回值类型等信息，就可以动态调用了。

　　添加如下WSHelper类，通过调用InvokeWebService方法，实现对接口的动态调用。

using System;
using System.Collections.Generic;
using System.Web;
using System.Net;
using System.IO;
using System.Web.Services.Description;
using System.CodeDom;
using Microsoft.CSharp;
using System.CodeDom.Compiler;
using System.Reflection;
using System.Xml;

namespace KellyZheng
{
    public class WSHelper
    {
        /// < summary>           
        /// 动态调用web服务         
        /// < /summary>          
        /// < param name="url">WSDL服务地址< /param> 
        /// < param name="methodname">方法名< /param>           
        /// < param name="args">参数< /param>           
        /// < returns>< /returns>          
        public static object InvokeWebService(string url, string methodname, object[] args)
        {
            return WSHelper.InvokeWebService(url, null, methodname, args);
        }
        /// < summary>          
        /// 动态调用web服务 
        /// < /summary>          
        /// < param name="url">WSDL服务地址< /param>
        /// < param name="classname">类名< /param>  
        /// < param name="methodname">方法名< /param>  
        /// < param name="args">参数< /param> 
        /// < returns>< /returns>
        public static object InvokeWebService(string url, string classname, string methodname, object[] args)
        {
            string @namespace = "KZWSDL";
            if ((classname == null) || (classname == ""))
            {
                classname = WSHelper.GetWsClassName(url);
            }
            try
            {                   //获取WSDL   
                WebClient wc = new WebClient();
                Stream stream = wc.OpenRead(url + "?WSDL");
                ServiceDescription sd = ServiceDescription.Read(stream);
                ServiceDescriptionImporter sdi = new ServiceDescriptionImporter();
                sdi.AddServiceDescription(sd, "", "");
                CodeNamespace cn = new CodeNamespace(@namespace);
                //生成客户端代理类代码          
                CodeCompileUnit ccu = new CodeCompileUnit();
                ccu.Namespaces.Add(cn);
                sdi.Import(cn, ccu);
                CSharpCodeProvider icc = new CSharpCodeProvider();
                //设定编译参数                 
                CompilerParameters cplist = new CompilerParameters();
                cplist.GenerateExecutable = false;
                cplist.GenerateInMemory = true;
                cplist.ReferencedAssemblies.Add("System.dll");
                cplist.ReferencedAssemblies.Add("System.XML.dll");
                cplist.ReferencedAssemblies.Add("System.Web.Services.dll");
                cplist.ReferencedAssemblies.Add("System.Data.dll");
                //编译代理类                 
                CompilerResults cr = icc.CompileAssemblyFromDom(cplist, ccu);
                if (true == cr.Errors.HasErrors)
                {
                    System.Text.StringBuilder sb = new System.Text.StringBuilder();
                    foreach (System.CodeDom.Compiler.CompilerError ce in cr.Errors)
                    {
                        sb.Append(ce.ToString());
                        sb.Append(System.Environment.NewLine);
                    }
                    throw new Exception(sb.ToString());
                }
                //生成代理实例，并调用方法   
                System.Reflection.Assembly assembly = cr.CompiledAssembly;
                Type t = assembly.GetType(@namespace + "." + classname, true, true);
                object obj = Activator.CreateInstance(t);
                System.Reflection.MethodInfo mi = t.GetMethod(methodname);
                return mi.Invoke(obj, args);
                // PropertyInfo propertyInfo = type.GetProperty(propertyname);     
                //return propertyInfo.GetValue(obj, null); 
            }
            catch (Exception ex)
            {
                throw new Exception(ex.InnerException.Message, new Exception(ex.InnerException.StackTrace));
            }
        }
        private static string GetWsClassName(string wsUrl)
        {
            string[] parts = wsUrl.Split('/');
            string[] pps = parts[parts.Length - 1].Split('.');
            return pps[0];
        }
    }
}