长时间动态调用WebService出错，郁闷

gtrabcd 2013-03-06 10:55:13

最近在搞WebService开发，发现了一个问题，通过下面这个WebServiceHelper类长时间调用WebService，会出现“未将实例引用到对象”的错误。（程序开始运行正常，但是时间长了就出现问题了，大概5小时左右），高手们给小弟指点下。
WebServiceHelper的代码如下：

using System.Net;

using System.CodeDom;

using System;

using System.IO;

using System.Web.Services.Description;

using Microsoft.CSharp;

using System.Reflection;

using System.CodeDom.Compiler;



namespace messageCenter

{

    public class WebServiceHelper

    {

        #region InvokeWebService

        /// < 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 WebServiceHelper.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 = "EnterpriseServerBase.WebService.DynamicWebCalling";

            if ((classname == null) || (classname == ""))

            {

                classname = WebServiceHelper.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);

                if (args[0] != "")

                    return mi.Invoke(obj, args);

                else

                    //Invoke(obj, BindingFlags.Default, new MyBinder(), new Object[] { (int)32, (int)32 }, CultureInfo.CurrentCulture);//这个是msdn上的，比较复杂有时间再琢磨。

                    return mi.Invoke(obj, BindingFlags.Default, null, null, null);



                /*   

                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];

        }

        #endregion   

    }

}