包含名称空间的XDocument

Question

我尝试使用XDocument查询以下XML：<E2ETraceEvent xmlns="http://schemas.microsoft.com/2004/06/E2ETraceEvent">    <System xmlns="http://schemas.microsoft.com/2004/06/windows/eventlog/system">        <EventID>589828</EventID>        <Type>3</Type>        <SubType Name="Information">0</SubType>        <Level>8</Level>        <TimeCreated SystemTime="2010-06-01T09:45:15.8102117Z" />        <Source Name="System.ServiceModel" />        <Correlation ActivityID="{00000000-0000-0000-0000-000000000000}" />        <Execution ProcessName="w3wp" ProcessID="5012" ThreadID="5" />        <Channel />        <Computer>TESTSERVER3A</Computer>    </System>    <ApplicationData>        <TraceData>            <DataItem>                <TraceRecord xmlns="http://schemas.microsoft.com/2004/10/E2ETraceEvent/TraceRecord" Severity="Information">                    <TraceIdentifier>http://msdn.microsoft.com/en-GB/library/System.ServiceModel.Activation.WebHostCompilation.aspx</TraceIdentifier>                    <Description>Webhost compilation</Description>                    <AppDomain>/LM/W3SVC/257188508/Root-1-129198591101343437</AppDomain>                    <Source>System.ServiceModel.Activation.ServiceParser/39498779</Source>                    <ExtendedData xmlns="http://schemas.microsoft.com/2006/08/ServiceModel/StringTraceRecord">                        <VirtualPath>/Service.svc</VirtualPath>                    </ExtendedData>                </TraceRecord>            </DataItem>        </TraceData>    </ApplicationData></E2ETraceEvent>执行以下代码将为xEl1返回null，除非我手动删除名称空间：XDocument xDoc = XDocument.Parse(CurrentString);XElement xEl1 = xDoc.Element("E2ETraceEvent");XElement xEl2 = xEl1.Element("System");XElement xEl3 = xEl2.Element("Correlation");XAttribute xAtt1 = xEl3.Attribute("ActivityID");String sValue = xAtt1.Value;您如何编写代码以提取XDocument中的Guid？