(PHP 5, PHP 7)
DOMDocument::createAttributeNS — Create new attribute node with an associated namespace
This function creates a new instance of class DOMAttr. 此节点出现在文档中,除非是用诸如 DOMNode->appendChild() 等函数来将其插入。
namespaceURIThe URI of the namespace.
qualifiedName
       The tag name and prefix of the attribute, as prefix:tagname.
      
   The new DOMAttr or FALSE if an error occurred.
  
DOM_INVALID_CHARACTER_ERR
       Raised if qualifiedName contains an invalid character.
      
DOM_NAMESPACE_ERR
       Raised if qualifiedName is a malformed qualified
       name, or if qualifiedName has a prefix and 
       namespaceURI is NULL.