public static object InvokeWebService( string url, string methodname, object [] args)
其中，url是Web服务的地址，methodname是要调用服务方法名，args是要调用Web服务所需的参数，返回值就是web服务返回的结果了。
要实现这样的功能，你需要这几个方面的技能：反射、CodeDom、编程使用C#编译器、WebService。在了解这些知识后，就可以容易的实现web服务的动态调用了： using System.CodeDom.Compiler; using System; using System.Net; using System.CodeDom; using Microsoft.CSharp; using System.IO; using System.Web.Services.Description; using System.Collections.Generic; using System.Reflection; namespace cjl.WebServices{ public class DynamicWebServices { static SortedList < string , Type > _typeList = new SortedList < string , Type > (); #region InvokeWebService static string GetCacheKey( string url, string className) { return url.ToLower() + className; } static Type GetTypeFromCache( string url, string className) { string key = GetCacheKey(url, className); foreach (KeyValuePair < string , Type > pair in _typeList) { if (key == pair.Key) { return pair.Value; } } return null ; } static Type GetTypeFromWebService( string url, string className) { string @namespace = " EnterpriseServerBase.WebService.DynamicWebCalling " ; if ((className == null ) || (className == "" )) { className = GetWsClassName(url); } // 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 csc = new CSharpCodeProvider(); ICodeCompiler icc = csc.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 = 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 ); return t; } // 动态调用web服务 public static object InvokeWebService( string url, string methodName, object [] args) { return InvokeWebService(url, null , methodName, args); } public static object InvokeWebService( string url, string className, string methodName, object [] args) { try { Type t = GetTypeFromCache(url, className); if (t == null ) { t = GetTypeFromWebService(url, className); // 添加到缓冲中 string key = GetCacheKey(url, className); _typeList.Add(key, t); } object obj = Activator.CreateInstance(t); MethodInfo mi = t.GetMethod(methodName); return mi.Invoke(obj, args); } 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 }}
上面的注释已经很好的说明了各代码段的功能，下面给个例子看看，这个例子是通过访问 服务来获取各大城市的天气状况。
string url = " http://www.webservicex.net/globalweather.asmx " ; string [] args = new string [ 2 ];args[ 0 ] = this .textBox_CityName.Text;args[ 1 ] = " China " ; object result = WebServiceHelper.InvokeWebService(url, " GetWeather " , args); this .label_Result.Text = result.ToString();