动态调用webservice时提示找不到函数解决方案

WebServiceInvoker invoker;
invoker = new WebServiceInvoker(new Uri(webservice));
object[] args = new object[] { 
                (object)ecgId, (object)data, (object)sampleRate, (object)adBit, (object)adRange, 
                (object)uVpb, (object)amp, (object)seconds, (object)filter, (object)deviceSn, 
                (object)clientType, (object)alias, (object)patientName, (object)patientAge,(object)patientSex };
bool result = invoker.InvokeMethod<bool>("EcgWebService", "SaveEcgData", args);
[code=C#]
现在碰到一个奇怪的错误，我之前的一个程序调用这个webservice的SaveEcgData函数是正常的。现在手头的程序调用webservice的SaveEcgData函数时，抛出异常，提示找不到这个方法。而我用代理类中的public List<string> EnumerateServiceMethods(string serviceName)方法列举函数列表时列表里是肯定包含有SaveEcgData函数的。

碰到这个问题很奇怪，我很难解释原因，请问这个找不到方法，是因为什么原因？


代理类
[code=C#]
using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;
using System.Xml;
using System.Web.Services.Description;
using Microsoft.CSharp;
using System.CodeDom.Compiler;
using System.CodeDom;

namespace TestClient
{
    class WebServiceInvoker
    {
        Dictionary<string, Type> availableTypes;

        /// <summary>
        /// Text description of the available services within this web service.
        /// </summary>
        public List<string> AvailableServices
        {
            get { return this.services; }
        }

        /// <summary>
        /// Creates the service invoker using the specified web service.
        /// </summary>
        /// <param name="webServiceUri"></param>
        public WebServiceInvoker(Uri webServiceUri)
        {
            this.services = new List<string>(); // available services
            this.availableTypes = new Dictionary<string, Type>(); // available types

            // create an assembly from the web service description
            this.webServiceAssembly = BuildAssemblyFromWSDL(webServiceUri);

            // see what service types are available
            Type[] types = this.webServiceAssembly.GetExportedTypes();

            // and save them
            foreach (Type type in types)
            {
                services.Add(type.FullName);
                availableTypes.Add(type.FullName, type);
            }
        }

        /// <summary>
        /// Gets a list of all methods available for the specified service.
        /// </summary>
        /// <param name="serviceName"></param>
        /// <returns></returns>
        public List<string> EnumerateServiceMethods(string serviceName)
        {
            List<string> methods = new List<string>();

            if (!this.availableTypes.ContainsKey(serviceName))
                throw new Exception("Service Not Available");
            else
            {
                Type type = this.availableTypes[serviceName];

                // only find methods of this object type (the one we generated)
                // we don't want inherited members (this type inherited from SoapHttpClientProtocol)
                foreach (MethodInfo minfo in type.GetMethods(BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly))
                    methods.Add(minfo.Name);

                return methods;
            }
        }

        /// <summary>
        /// Invokes the specified method of the named service.
        /// </summary>
        /// <typeparam name="T">The expected return type.</typeparam>
        /// <param name="serviceName">The name of the service to use.</param>
        /// <param name="methodName">The name of the method to call.</param>
        /// <param name="args">The arguments to the method.</param>
        /// <returns>The return value from the web service method.</returns>
        public T InvokeMethod<T>(string serviceName, string methodName, params object[] args)
        {
            // create an instance of the specified service
            // and invoke the method
            object obj = this.webServiceAssembly.CreateInstance(serviceName);

            Type type = obj.GetType();

            return (T)type.InvokeMember(methodName, BindingFlags.InvokeMethod, null, obj, args);
        }

        /// <summary>
        /// Builds the web service description importer, which allows us to generate a proxy class based on the 
        /// content of the WSDL described by the XmlTextReader.
        /// </summary>
        /// <param name="xmlreader">The WSDL content, described by XML.</param>
        /// <returns>A ServiceDescriptionImporter that can be used to create a proxy class.</returns>
        private ServiceDescriptionImporter BuildServiceDescriptionImporter(XmlTextReader xmlreader)
        {
            // make sure xml describes a valid wsdl
            if (!ServiceDescription.CanRead(xmlreader))
                throw new Exception("Invalid Web Service Description");

            // parse wsdl
            ServiceDescription serviceDescription = ServiceDescription.Read(xmlreader);

            // build an importer, that assumes the SOAP protocol, client binding, and generates properties
            ServiceDescriptionImporter descriptionImporter = new ServiceDescriptionImporter();
            descriptionImporter.ProtocolName = "Soap";
            descriptionImporter.AddServiceDescription(serviceDescription, null, null);
            descriptionImporter.Style = ServiceDescriptionImportStyle.Client;
            descriptionImporter.CodeGenerationOptions = System.Xml.Serialization.CodeGenerationOptions.GenerateProperties;

            return descriptionImporter;
        }

        /// <summary>
        /// Compiles an assembly from the proxy class provided by the ServiceDescriptionImporter.
        /// </summary>
        /// <param name="descriptionImporter"></param>
        /// <returns>An assembly that can be used to execute the web service methods.</returns>
        private Assembly CompileAssembly(ServiceDescriptionImporter descriptionImporter)
        {
            // a namespace and compile unit are needed by importer
            CodeNamespace codeNamespace = new CodeNamespace();
            CodeCompileUnit codeUnit = new CodeCompileUnit();

            codeUnit.Namespaces.Add(codeNamespace);

            ServiceDescriptionImportWarnings importWarnings = descriptionImporter.Import(codeNamespace, codeUnit);

            if (importWarnings == 0) // no warnings
            {
                // create a c# compiler
                CodeDomProvider compiler = CodeDomProvider.CreateProvider("CSharp");

                // include the assembly references needed to compile
                string[] references = new string[2] { "System.Web.Services.dll", "System.Xml.dll" };

                CompilerParameters parameters = new CompilerParameters(references);

                // compile into assembly
                CompilerResults results = compiler.CompileAssemblyFromDom(parameters, codeUnit);

                foreach (CompilerError oops in results.Errors)
                {
                    // trap these errors and make them available to exception object
                    throw new Exception("Compilation Error Creating Assembly");
                }

                // all done....
                return results.CompiledAssembly;
            }
            else
            {
                // warnings issued from importers, something wrong with WSDL
                throw new Exception("Invalid WSDL");
            }
        }

        /// <summary>
        /// Builds an assembly from a web service description.
        /// The assembly can be used to execute the web service methods.
        /// </summary>
        /// <param name="webServiceUri">Location of WSDL.</param>
        /// <returns>A web service assembly.</returns>
        private Assembly BuildAssemblyFromWSDL(Uri webServiceUri)
        {
            if (String.IsNullOrEmpty(webServiceUri.ToString()))
                throw new Exception("Web Service Not Found");

            XmlTextReader xmlreader = new XmlTextReader(webServiceUri.ToString() + "?wsdl");

            ServiceDescriptionImporter descriptionImporter = BuildServiceDescriptionImporter(xmlreader);

            return CompileAssembly(descriptionImporter);
        }

        private Assembly webServiceAssembly;
        private List<string> services;
    }
}