The global attribute 'http://www.w3.org/XML/1998/namespace:lang' has already been declared.???? 我想這個問題在做webservice時肯定有朋友遇見過吧，你們是怎么出來的，搜了很多外國的帖子，大概也試了一下，還是不行，在這里求教高手了。 ? 因為訪問沒有數(shù)據(jù)，我登錄webservice服務(wù)器，查看錯誤日志，具體如下： [2013-01-08 15:30:08]??? ErrorPage:====================================== [2013-01-08 15:30:10]??? Error Time: 1/8/2013 3:30:10 PM [2013-01-08 15:30:10]??? Error Url: http://ades-admin.go.com.hk/WebService/DataSetWebService.asmx [2013-01-08 15:30:10]??? Error Message: The global attribute 'http://www.w3.org/XML/1998/namespace:lang' has already been declared. [2013-01-08 15:30:12]?????? at System.Xml.Schema.XmlSchemaSet.InternalValidationCallback(Object sender, ValidationEventArgs e)?? at System.Xml.Schema.BaseProcessor.SendValidationEvent(XmlSchemaException e, XmlSeverityType severity)?? at System.Xml.Schema.BaseProcessor.AddToTable(XmlSchemaObjectTable table, XmlQualifiedName qname, XmlSchemaObject item)?? at System.Xml.Schema.Compiler.Prepare(XmlSchema schema, Boolean cleanup)?? at System.Xml.Schema.XmlSchemaSet.Compile()?? at System.Xml.Serialization.XmlSchemas.Compile(ValidationEventHandler handler, Boolean fullCompile)?? at System.Web.Services.Description.SchemaCompiler.Compile(XmlSchemas schemas)?? at System.Web.Services.Description.WebServicesInteroperability.AnalyzeDescription(ServiceDescriptionCollection descriptions, BasicProfileViolationCollection violations)?? at System.Web.Services.Description.WebServicesInteroperability.CheckConformance(WsiProfiles claims, ServiceDescriptionCollection descriptions, BasicProfileViolationCollection violations)?? at ASP.defaultwsdlhelpgenerator_aspx.Page_Load(Object sender, EventArgs e) in c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG\DefaultWsdlHelpGenerator.aspx:line 1439?? at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)?? at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)?? at System.Web.UI.Control.OnLoad(EventArgs e)?? at System.Web.UI.Control.LoadRecursive()?? at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)