如何动态调用WebService?
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今天在CSDN看到一个问题：如何动态调用WebService? （原贴见：http://community.csdn.net/Expert/topic/3330/3330006.xml?temp=.8463404） 方法一： 手动的添加一个Web引用，然后修改下本地的代理类。最后实现Web Service的URI部署到配置文件里。 具体做法如下： 以下代码是显示如何配置动态的Web Service，以服务单元C（类名为Web_SVSGC）为例： (1)???? 首先在Web引用中的本地代理类中添加一个构造函数，这个构造函数是以Web Service的URL为参数的重载方法。 Namespace Web_SVSGC ??? '<remarks/> ??? <System.Diagnostics.DebuggerStepThroughAttribute(),? _???? System.ComponentModel.DesignerCategoryAttribute("code"),? _???? System.Web.Services.WebServiceBindingAttribute(Name:="SVSGCSoap",[Namespace]:="http://tempuri.org/QYJSERVICE/SVSGC"),? _???? System.Xml.Serialization.XmlIncludeAttribute(GetType(Attribute))>? _ ??? Public Class SVSGC ??????? Inherits System.Web.Services.Protocols.SoapHttpClientProtocol ??? '<remarks/> ??????? Public Sub New() ??????????? MyBase.New ??????????? Me.Url = "http://localhost/QYJSERVICE/WEBSERVICE/SERVICE/SVSGC.asmx" ??????? End Sub
??????? '添加一个带参数的构造函数。 ??????? Public Sub New(ByVal strUrl As String)? ??????????? MyBase.New()? ??????????? Me.Url = strUrl? ??????? End Sub ??(2)???? 将Web Service的url配置在调用Web Service的应用程序的配置文件中。（其中的value可以随时修改。） <configuration> ??? <appSettings> ????????????? <add key="SVSGA_URL" value="http://192.168.108.188/?QDN/SERVICE/SVSGA.asmx"?QDN/SERVICE/SVSGA.asmx" /> ????</appSettings> </configuration> ?(3)???? 调用时，根据配置文件的Url动态的生成Web Service。 ??????? '要调用的Web Service的URL ??????? Dim strWebSvsUrl As String ??????? '声明一个要调用的Web Service ??????? Dim objSVSGC As WebSvs_GC. SVSGC ??????? '调用Web Service的远程方法的返回值 ??????? Dim strReturnValue As String ??????? Try ????????????'从配置文件中取得Web Service的URL ??????????? strWebSvsUrl = _? ??????????? System.Configuration.ConfigurationSettings.AppSettings("SVSGC_URL")? ??????????? '生成一个Web Service实例 ??????????? objSVSGC = New WebSvs_GC.SVSGC (strWebSvsUrl) ??????????? '调用这个Web Service里的远程方法 ??????????? strReturnValue = objSVSGC.HelloWorld() ??????? Catch ex As Exception ??????? End Try 方法二：利用了CodeDem动态的编译出Web Service的代理类来，方法还是很不错的哦。缺点是因为类型定义都在内存里动态生成，所以返回值复杂的调用无法实现。 /// <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)); ??? ??? ??? } ??? ??? } 方法三：URL Behavior 属性 项目中的每一 Web 引用都与一个代理类进行交互，该代理类用于访问 Web 服务的内容。可以使用 UrlBehavior 属性来控制代理类获取特定 Web 引用的 URL 的方式。该属性具有两项设置：
将Web引用改为Dynamic的，本地的代理会被修改： ??? ??? Public Sub New() ??? ??? ??? MyBase.New ??? ??? ??? Dim urlSetting As String = System.Configuration.ConfigurationSettings.AppSettings("CallWebServiceDemo.WebServiceDemo.Service1") ??? ??? ??? If (Not (urlSetting) Is Nothing) Then ??? ??? ??? ??? Me.Url = String.Concat(urlSetting,"") ??? ??? ??? Else ??? ??? ??? ??? Me.Url = "http://localhost/WebAppTest/WebServiceDemo/Service1.asmx" ??? ??? ??? End If ??? ??? End Sub urlSetting 被追加了。你只要按照Key（CallWebServiceDemo.WebServiceDemo.Service1），在相应的.config里追加此Key/Value就可以了。 （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |