Question

I am trying to select specific values from a xml document using XPath. The xml is stored into a string varibale “tmp”. This xml is the result of a query performed on a external API.

sample XML contents:

<?xml version="1.0" encoding="ISO-8859-1"?>
<Results>
<Checks>
<Check id="wbc">
<Linespeed>6000 </Linespeed>
<Provider>BT WBC </Provider>
</Check>
<Check id="adsl">
<Linespeed>2048 </Linespeed>
<Provider>BT ADSL </Provider>
</Check>
</Checks>
</Results>

Using XPATH in code behind I want to be able to select the and only for id=adsl, then store the value in a string variable for later use. I want to achieve this withouth the use of a separate xslt stylesheet.

Here is the code I have written for this but I am getting an error:

//Creating an XPATH epression
String strExpression1;
strExpression1 = "Results/Checks/Check[@id = 'adsl']/Linespeed";

//Loading the xml document
XmlDocument doc;
doc = new XmlDocument();
doc.LoadXml(tmp);

//Create an XmlNamespaceManager to resolve the default namespace.
XmlNamespaceManager nsmgr = new XmlNamespaceManager(doc.NameTable);
nsmgr.AddNamespace("bk", "urn:schemas-microsoft-com:xslt");

//Selecting Linespeed from Check id='adsl'
XmlNode Check;
XmlElement root = doc.DocumentElement;
Check = root.SelectSingleNode(strExpression1, nsmgr);

//Assigning the the results of the XPATH expression to the variable Linespeedval
string Linespeedval = Check.ToString();

//Adding a control to display the xpath results of the "tmp" xml objectt
AvailabilityCheckerResults2.Controls.Add(new LiteralControl(Linespeedval));

Any assistance will be greately appreciated! Thanks in advance!

Answer 1

strExpression1 = "/Results/Checks/Check[@id = 'adsl']/Linespeed";
//or strExpression1 = "//Checks/Check[@id = 'adsl']/Linespeed";
//doc has no namespace
Check = root.SelectSingleNode(strExpression1);
....
string Linespeedval = Check.InnerText;