忽略 LINQtoXML 中的名称空间

Instead of writing:

nodes.Elements("Foo")

write:

nodes.Elements().Where(e => e.Name.LocalName == "Foo")

and when you get tired of it, make your own extension method:

public static IEnumerable<XElement> ElementsAnyNS<T>(this IEnumerable<T> source, string localName)
where T : XContainer
{
return source.Elements().Where(e => e.Name.LocalName == localName);
}

Ditto for attributes, if you have to deal with namespaced attributes often (which is relatively rare).

[EDIT] Adding solution for XPath

For XPath, instead of writing:

/foo/bar | /foo/ns:bar | /ns:foo/bar | /ns:foo/ns:bar

you can use local-name() function:

/*[local-name() = 'foo']/*[local-name() = 'bar']

Here's a method to strip namespaces:

private static XElement StripNamespaces(XElement rootElement)
{
foreach (var element in rootElement.DescendantsAndSelf())
{
// update element name if a namespace is available
if (element.Name.Namespace != XNamespace.None)
{
element.Name = XNamespace.None.GetName(element.Name.LocalName);
}


// check if the element contains attributes with defined namespaces (ignore xml and empty namespaces)
bool hasDefinedNamespaces = element.Attributes().Any(attribute => attribute.IsNamespaceDeclaration ||
(attribute.Name.Namespace != XNamespace.None && attribute.Name.Namespace != XNamespace.Xml));


if (hasDefinedNamespaces)
{
// ignore attributes with a namespace declaration
// strip namespace from attributes with defined namespaces, ignore xml / empty namespaces
// xml namespace is ignored to retain the space preserve attribute
var attributes = element.Attributes()
.Where(attribute => !attribute.IsNamespaceDeclaration)
.Select(attribute =>
(attribute.Name.Namespace != XNamespace.None && attribute.Name.Namespace != XNamespace.Xml) ?
new XAttribute(XNamespace.None.GetName(attribute.Name.LocalName), attribute.Value) :
attribute
);


// replace with attributes result
element.ReplaceAttributes(attributes);
}
}
return rootElement;
}

Example usage:

XNamespace ns = "http://schemas.domain.com/orders";
XElement xml =
new XElement(ns + "order",
new XElement(ns + "customer", "Foo", new XAttribute("hello", "world")),
new XElement("purchases",
new XElement(ns + "purchase", "Unicycle", new XAttribute("price", "100.00")),
new XElement("purchase", "Bicycle"),
new XElement(ns + "purchase", "Tricycle",
new XAttribute("price", "300.00"),
new XAttribute(XNamespace.Xml.GetName("space"), "preserve")
)
)
);


Console.WriteLine(xml.Element("customer") == null);
Console.WriteLine(xml);
StripNamespaces(xml);
Console.WriteLine(xml);
Console.WriteLine(xml.Element("customer").Attribute("hello").Value);

As I found this question in search for an easy way to ignore namespaces on attributes, here's an extension for ignoring namespaces when accessing an attribute, based on Pavel´s answer (for easier copying, I included his extension):

public static XAttribute AttributeAnyNS<T>(this T source, string localName)
where T : XElement
{
return source.Attributes().SingleOrDefault(e => e.Name.LocalName == localName);
}


public static IEnumerable<XElement> ElementsAnyNS<T>(this IEnumerable<T> source, string localName)
where T : XContainer
{
return source.Elements().Where(e => e.Name.LocalName == localName);
}