c# - Namespace redefinition exception if XmlTextWriter is declared a certain way -

i bulding xdocument , serializing utf8 string following code:

string xmlstring = ""; using (memorystream ms = new memorystream()) {   using (xmlwriter xw = new xmltextwriter(ms, encoding.utf8))   {     doc.save(xw);     xw.flush();     streamreader sr = new streamreader(ms);     ms.seek(0, seekorigin.begin);     xmlstring = sr.readtoend();   } } 

this worked fine.

i needed toggle whether or not declarator serialized string. changed code this:

string xmlstring = ""; using (memorystream ms = new memorystream()) {   xmlwritersettings settings = new xmlwritersettings()   {     omitxmldeclaration = !root.includedeclarator,     encoding = encoding.utf8   };   using (xmlwriter xw = xmltextwriter.create(ms, settings))   {     doc.save(xw);     xw.flush();     streamreader sr = new streamreader(ms);     ms.seek(0, seekorigin.begin);     xmlstring = sr.readtoend();   } } 

this throws following exception on doc.save(xw):

the prefix '' cannot redefined '' 'my_schema_here' within same start element tag.

i trying figure out why xdoc can saved if writer "new"ed up, not if ".create"d. ideas?

jordon

i fixed adding namespace name of root element in xdocument. still, it's strange isn't necessary if "new xmltextwriter()" used instead of "xmltextwriter.create()" or "xmlwriter.create()".

jordon