如何动态调用WebServices

引言: 一般的WebService引用 都是在已经知道服务页面的名称(例如:我的服务.asmx)和方法的名称(如: 

[WebMethod]
    public string TestDatabase()

本文说的是另外一种情形: 就是动态调用WebServices

简单说: URL地址和方法的名称 都是作为参数动态传入的

using System.Web.Services.Description;
using System.CodeDom;
using Microsoft.CSharp;
using System.CodeDom.Compiler;

private static string GetWsClassName(string wsUrl)
        {
            string[] parts = wsUrl.Split('/');
            string[] pps = parts[parts.Length - 1].Split('.');

            return pps[0];
        }

 public static object InvokeWebService(string methodname, object[] args,string url)
        {
            //string @namespace = "EnterpriseServerBase.WebService.DynamicWebCalling";
            //string url = HttpContext.Current.Session["weburl"].ToString().Trim();
            //string url = DataOperation.GetSession("weburl").ToString().Trim();
            string classname = 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();

                //生成客户端代理类代码
                CodeCompileUnit ccu = new CodeCompileUnit();
                ccu.Namespaces.Add(cn);
                sdi.Import(cn, ccu);
                //CSharpCodeProvider csc = new CSharpCodeProvider();
                CodeDomProvider provider = CodeDomProvider.CreateProvider("CSharp");
               // ICodeCompiler icc = provider.CreateCompiler();    

               

                //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 = provider.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(classname, true, true);
                object obj = Activator.CreateInstance(t);
                System.Reflection.MethodInfo mi = t.GetMethod(methodname);

                return mi.Invoke(obj, args);
            }
            catch (Exception ex)
            {
                //throw new Exception(ex.InnerException.Message, new Exception(ex.InnerException.StackTrace));

                return "Error:WebService调用错误！"+ex.Message;
            }
        }