Looks up the closest xmlns declaration for the given namespace URI that is in scope for the current node and returns the prefix defined in the declaration.

Standard HTML nodes will always have the default namespace to simplify XPath queries even if an xmlns is explicitely specified in XHTML documents.
For all non-standard HTML 4.01 elements that define an xmlns, NamespaceURI will return the namespace URI.

public string GetPrefixOfNamespace(
	string namespaceUri
)

Public Function GetPrefixOfNamespace ( _
	namespaceUri As String _
) As String

public:
String^ GetPrefixOfNamespace(
	String^ namespaceUri
)