Use XmlReader to just get children

Question

I have this XML:

<root>
  <row>
     <data1>Data</data1>
     <data2>Data</data2>
     <data3>Data
         <subdata>SubData</subdata>
     </data3>
  </row>
</root>

and I want to use an XmlReader to read only the <dataX> elements, without knowing the exact name of dataX. I found the ReadToNextSibling method, but it needs a name, which I do not know.

Answer 1

You can use the following XPath to filter the elements to just the <dataN> elements:

/root/row/*[substring(name(), 0,5) = 'data']

/root/row/*[starts-with(name(),'data')]

However, XmlReader cannot use xPath nor wildcards for element names in any of its navigation methods such as ReadToNextSibling

---

You could use XPathReader, which can be instantiated from an XmlReader object, as follows:

XPathReader xpr  = new XPathReader("MyXml.xml", "/root/row/*[substring(name(), 0,5) = 'data']"); 

while (xpr.ReadUntilMatch()) {
   Console.WriteLine(xpr.ReadString()); 
} 

(You can download XPathReader from Microsoft here: https://www.microsoft.com/en-us/download/details.aspx?id=22677)

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If you don't like the idea of XPathReader, you can do the following with XmlDocument:

XmlDocument xDoc = new XmlDocument();
xDoc.LoadXml(xml);
XmlNode root = xDoc.DocumentElement;

foreach (XmlNode item in root.SelectNodes(@"/root/row/*[substring(name(),0,5) = 'data']"))
{
    Console.WriteLine(item.Value);
}

---

EDIT

A better XPath would actually be:

/root/row/*[starts-with(name(),'data')]