问题
I'm loading a string to an XML document that contains the following structure :
<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<ItemGroup>
<Compile Include="clsWorker.cs" />
</ItemGroup>
</Project>
then im loading all into xmldocument :
XmlDocument xmldoc = new XmlDocument();
xmldoc.LoadXml(Xml);
then the following problem occurs :
XmlNode Node = xmldoc.SelectSingleNode("//Compile"); // return null
when i remove the xmlns attribute from the root element(Project) its working fine, how can i improve my SelectSingleNode to return the relevant element ?
回答1:
You should use an XmlNamespaceManager in your call to SelectSingleNode():
XmlNamespaceManager ns = new XmlNamespaceManager(xmldoc.NameTable);
ns.AddNamespace("msbld", "http://schemas.microsoft.com/developer/msbuild/2003");
XmlNode node = xmldoc.SelectSingleNode("//msbld:Compile", ns);
回答2:
Taken right from the documentation of SelectSingleNode() on the MSDN:
Note
If the XPath expression does not include a prefix, it is assumed that the namespace URI is the empty namespace. If your XML includes a default namespace, you must still add a prefix and namespace URI to the XmlNamespaceManager; otherwise, you will not get a node selected. For more information, see Select Nodes Using XPath Navigation.
And the immediately following sample code is
XmlNamespaceManager nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("ab", "http://www.lucernepublishing.com");
XmlNode book = doc.SelectSingleNode("//ab:book", nsmgr);
It's not as if this would be "hidden knowledge". ;-)
回答3:
Since the 'ItemGroup' may have multiple 'Compile' children, and you specifically want the 'Compile' children of 'Project/ItemGroup', the following will return all of the desired 'Compile' children and no others:
XmlDocument projectDoc = new XmlDocument();
projectDoc.Load(projectDocPath);
XmlNamespaceManager ns = new XmlNamespaceManager(projectDoc.NameTable);
ns.AddNamespace("msbld", "http://schemas.microsoft.com/developer/msbuild/2003");
XmlNodeList xnList = projectDoc.SelectNodes(@"/msbld:Project/msbld:ItemGroup/msbld:Compile", ns);
Note that the 'msbld:' namespace specification needs to precede each node level.
回答4:
This way you don't need to specify namespace:
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml("your xml");
XmlNode node = xmlDoc.SelectSingleNode("/*[local-name() = 'Compile']");
XmlNode nodeToImport = xmlDoc2.ImportNode(node, true);
xmlDoc2.AppendChild(nodeToImport);
来源:https://stackoverflow.com/questions/47829282/how-to-get-xml-tag-which-is-in-dataset1-tagc