XML traversing using XmlDocument

Question

I have the following code, which I use to traverse the XML:

private void btn_readXML_Click(object sender, EventArgs e)
{
        var doc = new XmlDocument();
        doc.Load("e:\\contacts.xml");
        // Load xml document.            
        TraverseNodes(doc.ChildNodes);     
}

static List<string> xmlnodes = new List<string>();
private static void TraverseNodes(XmlNodeList nodes)
{     
       foreach (XmlNode node in nodes)
       {                   
              List<string> temp = new List<string>();                  
              temp.Add("Node name: " + node.Name.ToString());
              XmlAttributeCollection xmlAttributes = node.Attributes;

              foreach (XmlAttribute at in xmlAttributes)
              {
                   temp.Add("  Atrib: " + at.Name + ": " + at.Value);
              }

               xmlnodes.AddRange(temp);
               TraverseNodes(node.ChildNodes);     
}

But my problem is, I don't want to traverse the whole document, I only want to traverse the node and subsequently its children which has an attribute 'X'. Please note that I don't know where the node is present. So basically what I have to do is, find out if the node exists ( it'll have the attribute 'X'. That's how I identify its the right node) if yes then fetch its children.

Can anyone help me out here? I'm pretty new to XMLs. Thanks is advance!

Answer 1

Assuming your XML having following structure:

<Contacts>
   <Contact X="abc">
       <Child1></Child1>
   </Contact>

   <Contact X="def">
       <Child2></Child2>
   </Contact>
</Contacts>

Example code using XmlNode.SelectNodes:

var doc = new XmlDocument();
doc.Load("e:\\contacts.xml");

//get root element of document   
XmlElement root = doc.DocumentElement;
//select all contact element having attribute X
XmlNodeList nodeList = root.SelectNodes("//Contact[@X]");
//loop through the nodelist
foreach (XmlNode xNode in nodeList)
{       
    //traverse all childs of the node
}

For different XPath Queries see this link.

UPDATE:

If you want to select all elements having attribute X in the document. No matters where they exists. You could use following:

//select all elements in the doucment having attribute X
XmlNodeList nodeList = root.SelectNodes("//*[@X]");