动态调用WebService(转载)

转载自：http://www.cnblogs.com/juqiang/archive/2004/08/30/37675.html

 /**//// <summary>
        /// 根据指定的信息，调用远程WebService方法
        /// </summary>
        /// <param name="url">WebService的http形式的地址</param>
        /// <param name="namespace">欲调用的WebService的命名空间</param>
        /// <param name="classname">欲调用的WebService的类名（不包括命名空间前缀）</param>
        /// <param name="methodname">欲调用的WebService的方法名</param>
        /// <param name="args">参数列表</param>
        /// <returns>WebService的执行结果</returns>
        /// <remarks>
        /// 如果调用失败，将会抛出Exception。请调用的时候，适当截获异常。
        /// 异常信息可能会发生在两个地方：
        /// 1、动态构造WebService的时候，CompileAssembly失败。
        /// 2、WebService本身执行失败。
        /// </remarks>
        /// <example>
        /// <code>
        /// object obj = InvokeWebservice("http://localhost/GSP_WorkflowWebservice/common.asmx",
                                 "Genersoft.Platform.Service.Workflow","Common","GetToolType",new object[]{"1"});
        /// </code>
        /// </example>
        public static object InvokeWebservice(string url, string @namespace, string classname, 
                                                                      string methodname, object[] args)        {        
            try
            {
                System.Net.WebClient wc = new System.Net.WebClient();
                System.IO.Stream stream = wc.OpenRead(url+"?WSDL");
                System.Web.Services.Description.ServiceDescription sd = 
                                 System.Web.Services.Description.ServiceDescription.Read(stream);
                System.Web.Services.Description.ServiceDescriptionImporter sdi = 
                                 new System.Web.Services.Description.ServiceDescriptionImporter();
                sdi.AddServiceDescription(sd,"","");
                System.CodeDom.CodeNamespace cn = new System.CodeDom.CodeNamespace(@namespace);
                System.CodeDom.CodeCompileUnit ccu = new System.CodeDom.CodeCompileUnit();
                ccu.Namespaces.Add(cn);
                sdi.Import(cn,ccu);

                Microsoft.CSharp.CSharpCodeProvider csc = new Microsoft.CSharp.CSharpCodeProvider();
                System.CodeDom.Compiler.ICodeCompiler icc = csc.CreateCompiler();

                System.CodeDom.Compiler.CompilerParameters cplist = 
                                    new System.CodeDom.Compiler.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");

                System.CodeDom.Compiler.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());
                }
                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);
            }
            catch(Exception ex)
            {
                throw new Exception(ex.InnerException.Message,new Exception(ex.InnerException.StackTrace));
            }
        }