SSS SSS - 3 months ago 19
C# Question

XML Document SelectSingleNode returns null

I am trying to read XML from stream reader and am also getting response XML. But when i try to read its nodes it is always returning null.

var request = (HttpWebRequest) WebRequest.Create(address);
var response = (HttpWebResponse) request.GetResponse();
var stream = response.GetResponseStream();

if(stream != null)
{
var xmlReader = new XmlTextReader(stream);
var xmlDocument = new XmlDocument();
xmlDocument.Load(xmlReader);
var node = xmlDocument.SelectSingleNode("RateQuote");
}


XML Document

<RateQuoteResponse xmlns="http://ratequote.usfnet.usfc.com/v2/x1">
<STATUS>
<CODE>0</CODE>
<VIEW>SECURED</VIEW>
<VERSION>...</VERSION>
</STATUS>
<RateQuote>
<ORIGIN>
<NAME>KNOXVILLE</NAME>
<CARRIER>USF Holland, Inc</CARRIER>
<ADDRESS>5409 N NATIONAL DR</ADDRESS>
<CITY>KNOXVILLE</CITY>
<STATE>TN</STATE>
<ZIP>37914</ZIP>
<PHONE>8664655263</PHONE>
<PHONE_TOLLFREE>8006545963</PHONE_TOLLFREE>
<FAX>8656379999</FAX>
</ORIGIN>
<DESTINATION>
<NAME>KNOXVILLE</NAME>
<CARRIER>USF Holland, Inc</CARRIER>
<ADDRESS>5409 N NATIONAL DR</ADDRESS>
<CITY>KNOXVILLE</CITY>
<STATE>TN</STATE>
<ZIP>37914</ZIP>
<PHONE>8664655263</PHONE>
<PHONE_TOLLFREE>8006545963</PHONE_TOLLFREE>
<FAX>8656379999</FAX>
</DESTINATION>
<ORIGIN_ZIP>37914</ORIGIN_ZIP>
<DESTINATION_ZIP>37909</DESTINATION_ZIP>
<TOTAL_COST>99.24</TOTAL_COST>
<SERVICEDAYS>1</SERVICEDAYS>
<INDUSTRYDAYS>1.6</INDUSTRYDAYS>
<CLASSWEIGHT>
<CLASS>55</CLASS>
<ASCLASS>50</ASCLASS>
<WEIGHT>100</WEIGHT>
<CHARGES>0.0</CHARGES>
</CLASSWEIGHT>
</RateQuote>
</RateQuoteResponse>

Answer

The XML document uses the default namespace "http://ratequote.usfnet.usfc.com/v2/x1". You need to change the SelectSingleNode call to use this namespace.

You need to setup a namspace manager and then supply it to SelectSingleNode.

var nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("rate", "http://ratequote.usfnet.usfc.com/v2/x1");
var node = xmlDocument.SelectSingleNode("//rate:RateQuote", nsmgr);

EDIT The RateQuoteResponse element has a default namespace xmlns="...". This means that all elements use this namespace also, unless specifically overridden.