- A+
所属分类：.NET技术
通常我们在程序中需要调用WebService时，都是通过“添加Web引用”，让VS.NET环境来为我们生成服务代理，然后调用对应的Web服务。这样是使工作简单了，但是却和提供Web服务的URL、方法名、参数绑定在一起了，这是VS.NET自动为我们生成Web服务代理的限制。如果哪一天发布Web服务的URL改变了，则我们需要重新让VS.NET生成代理，并重新编译。在某些情况下，这可能是不能忍受的，我们需要动态调用WebService的能力。比如我们可以把Web服务的URL保存在配置文件中，这样，当服务URL改变时，只需要修改配置文件就可以了
参考
用C#通过反射实现动态调用WebService 告别Web引用
动态调用WebService(C#)
public class WebServiceHelper { /// <summary> /// 动态调用web服务 /// </summary> /// <param name="url">url 网址</param> /// <param name="methodname">方法名</param> /// <param name="args">参数</param> /// <returns></returns> public static object InvokeWebServiceDynamic(string url, string methodname, object[] args) { return InvokeWebService(url, string.Empty, methodname, args); } 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 { InstanceInfo instance = GetInstanceInfo(@namespace, classname, methodname); if (instance != null) { return instance.InstanceMethod.Invoke(instance.Instance, args); } //获取WSDL WebClient wc = new WebClient(); Stream stream = wc.OpenRead(url + "?WSDL"); ServiceDescription sd = ServiceDescription.Read(stream); wc.Dispose(); stream.Close(); 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(); csc.Dispose(); //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); CompilerResults cr = csc.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); InstanceInfo newInstance = new InstanceInfo() { ClassName = classname, MethodName = methodname, NameSpace = @namespace, InstanceType = t, InstanceMethod = mi, Instance = obj }; _curInstanceInfo.Add(newInstance); return mi.Invoke(obj, args); } catch (Exception ex) { throw new Exception(ex.InnerException.Message, new Exception(ex.InnerException.StackTrace)); } } private static List<InstanceInfo> _curInstanceInfo = new List<InstanceInfo>(); private static InstanceInfo GetInstanceInfo(string nameSpace, string className, string methodName) { if (_curInstanceInfo.Exists(i => i.ClassName.Equals(className) && i.NameSpace.Equals(nameSpace) && i.MethodName.Equals(methodName))) { return _curInstanceInfo.FirstOrDefault( i => i.ClassName.Equals(className) && i.NameSpace.Equals(nameSpace) && i.MethodName.Equals(methodName)); } else { return null; } } private static string GetWsClassName(string wsUrl) { string[] parts = wsUrl.Split('/'); string[] pps = parts[parts.Length - 1].Split('.'); return pps[0]; } } public class InstanceInfo { /// <summary> /// 命名空间 /// </summary> public string NameSpace { get; set; } /// <summary> /// 类名 /// </summary> public string ClassName { get; set; } /// <summary> /// 方法名 /// </summary> public string MethodName { get; set; } /// <summary> /// 实例类型 /// </summary> public Type InstanceType { get; set; } /// <summary> /// 需要调用的方法 /// </summary> public System.Reflection.MethodInfo InstanceMethod { get; set; } public object Instance { get; set; } }
调用
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() ;
