I am receiving 'xsi' is an undeclared prefix using XmlDocument.
I am trying to read a file which has the following schema:
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2"
     xmlns:gx="http://www.google.com/kml/ext/2.2" 
     xmlns:kml="http://www.opengis.net/kml/2.2"
     xmlns:atom="http://www.w3.org/2005/Atom">
        <Document>
            <Document id="robert" xsi:schemaLocation="http://www.opengis.net/kml/2.2 http://schemas.opengis.net/kml/2.2.0/ogckml22.xsd http://www.google.com/kml/ext/2.2 http://code.google.com/apis/kml/schema/kml22gx.xsd">
              <Placemark>
                <description>test</description>
              </Placemark>
        </Document>
    </Document>
</kml>
I have tried the following:
    XmlDocument xmldoc = new XmlDocument();
    using (XmlTextReader tr = new XmlTextReader(strXmlFile))
    {
        //tr.Namespaces = false; (uncomment to ignore namespace)
        xmldoc.Load(tr);  // 'xsi' is an undeclared prefix error here
    }
If I uncomment the line to ignore the namespace, it loads ok but fails to save the XmlDocument later on.  So ignoring it would not be a solution.  Does anyone know how to properly load the schema?  The issue/error appears to be in this node:
<Document id="robert" xsi:schemaLocation="http://www.opengis.net/kml/2.2 http://schemas.opengis.net/kml/2.2.0/ogckml22.xsd http://www.google.com/kml/ext/2.2 http://code.google.com/apis/kml/schema/kml22gx.xsd">
Update #1 I tried the following:
XmlDocument xmldoc = new XmlDocument();
NameTable nt = new NameTable();
XmlNamespaceManager nsmgr = new XmlNamespaceManager(nt);
nsmgr.AddNamespace("xsi", "http://www.w3.org/2001/XMLSchema-instance");
XmlParserContext context = new XmlParserContext(null, nsmgr, null, XmlSpace.None);
XmlReaderSettings xset = new XmlReaderSettings();
xset.ConformanceLevel = ConformanceLevel.Fragment;
XmlReader rd = XmlReader.Create(new StringReader(strXmlFile), xset, context);
xmldoc.Load(rd);  // error is still on this line
But am receiving this error now:
"The specified node cannot be inserted as the valid child of this node, because the specified node is the wrong type." It looks like I am getting closer...