XDocument Namespace on root and first child

Question

I'm building an xml file using XDocument

XDocument single = new XDocument(
                new XDeclaration("1.0", "UTF-8", "true"),
                new XElement(_namespace + "vcards",
                    XElement.Parse(BuildCardEntry(contact))));

Inside BuildCardEntry(contact) I'm adding the namespace to every XElement too. But my code pruduces this

<vcards xmlns="urn:ietf:params:xml:ns:vcard-3.0">
  <vcard xmlns="urn:ietf:params:xml:ns:vcard-3.0">

insted of this

<vcards xmlns="urn:ietf:params:xml:ns:vcard-3.0">
  <vcard>

Does somebody know, how to solve this?

Answer 1

保存xml时，请使用SaveOptions.OmitDuplicateNamespaces参数。

single.Save(..., SaveOptions.OmitDuplicateNamespaces);