以相同的名称读取不同级别的XML节点

Question

i have an xml, which is have same element name at different level, i try to read it by using this code,

 xDoc.Load(url);
     XmlNodeList nodeList = xDoc.SelectNodes(string.Format("/DirectionsResponse/route"));
    foreach (XmlNode node in nodeList)
    {
        XmlElement companyElement = (XmlElement)node;

        kl = companyElement.GetElementsByTagName("summary")[0].InnerText;
        kl = companyElement.GetElementsByTagName("distance")[0].InnerText;
    }

i can read the summary element, but the problem is with the <distance> element, it read the first <distance> node that it found. I want to read the <distance> element that not in <step> node.

Can anyone show me how to do it

Answer 1

From MSDN, on GetElementsByTagName :

Returns an XmlNodeList containing a list of all descendant elements that match the specified Name.

It's a complete sub-tree search , not a "select subnodes" function. For selecting a single subnode, use SelectSingleNode . For a group like your "step" ones, use SelectNodes and iterate over them properly.

Answer 2

You can use SelectSingleNode or SelectNodes in order to describe elements in XPath just like you have done this at line XmlNodeList nodeList = xDoc.SelectNodes("/DirectionsResponse/route"); .

xDoc.Load(url);
XmlNodeList nodeList = xDoc.SelectNodes(string.Format("/DirectionsResponse/route"));
foreach (XmlNode node in nodeList)
{
    XmlElement companyElement = (XmlElement)node;

    kl = companyElement.SelectSingleNode("summary").InnerText; // summary node within current context
    kl = companyElement.SelectSingleNode("distance").InnerText;
}

should do the trick.

In my opinion, it is better to use all-purpose XPath SelectSingleNode and SelectNodes methods everywhere.
If you have any questions, read more about XPath at MSDN .

By the way , you can specify XmlElement as enumerated type and not convert it explicitly:

xDoc.Load(url);
foreach (XmlElement element in xDoc.SelectNodes("/DirectionsResponse/route")) 
{
    kl = element.SelectSingleNode("summary").InnerText;
    kl = element.SelectSingleNode("distance").InnerText;
}