请大家帮忙解释下代码
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 ex; }