c# - why add xmlns="" in the attribute of a node? -

i using c# , xdcoument add nodes root element. use code:

xelement mianimalnuevo = new xelement("principalnode",                 new xattribute("atribute1", "value attribute 1"),                 new xattribute("attribute2", "value attribute 2"),                 new xelement("subnode","0000")); 

but this:

<principalnode atribute1="value attribute 1" attribute2="value attribute 2" xmlns="">     <subnode>0000</subnode>   </principalnode> 

after attribute 2, see xmlns="". why? want attributes.

thanks.

this happens when have xml document has namespace defined somewhere tree.

adding element not in namespace in empty namespace (i.e., no namespace) add empty xmlns attribute.

<xml xmlns="some_namespace_uri">   <foo>the foo element inherits 'some_namespace_uri' namespace</foo>   <bar xmlns="">the bar element in no namespace</bar> </xml> 

related: is xmlns="" valid xml namespace?