Get value from node with same name

问题:

I'd like to retrieve information from an XML file, however the way it's formatted is pretty strange. Here it is...

<?xml version="1.0"?>
<Careers>
    <CareerList>
        <CareerName></CareerName>
        <CareerDescription></CareerDescription>
    </CareerList>
    <CareerList>
        <CareerName>Cook</CareerName>
        <CareerDescription>Cooks food for people</CareerDescription>
    </CareerList>
</Careers>

I'd like to get the 2nd value, which would be Cook and the description which is Cooks food for people, but instead I'm getting only the empty node. For example...

    public string CareerDescription(string CareerFile)
    {
        XmlDocument xmlDoc = new XmlDocument();
        xmlDoc.Load(CareerFile);
        string Description = xmlDoc.SelectSingleNode("Careers/CareerList/CareerDescription").InnerText;
        return Description;
    }

How would I select the second node instead of the first?

回答1:

You can use an index in your XPath expression:

xmlDoc.SelectSingleNode("Careers/CareerList[2]/CareerDescription").InnerText

Personally I'd use LINQ to XML instead, mind you:

var doc = XDocument.Load(CareerFile);
return doc.Root
          .Elements("CareerList")
          .ElementAt(1) // 0-based
          .Element("CareerDescription")
          .Value;

回答2:

Instead of SelectSingleNode you should use SelectNodes: it will return XmlNodeList nodeList. Then you should take the InnerText of the element from that node list with index [1];

public string CareerDescription(string CareerFile)
{
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(CareerFile);
string Description = xmlDoc.SelectNodes("Careers/CareerList/CareerDescription")[1].InnerText;
return Description;
}

Refer to the documentation on this method on MSDN for more details: http://msdn.microsoft.com/en-us/library/system.xml.xmlnode.selectnodes%28v=vs.71%29.aspx

回答3:

Just a straight way of LINQ to XML routine (and because it is LINQ, I prefer this way much more than the "standard" usage of XmlDocument with the support of XPath):

return XDocument.Load(CareerFile)
                .Descendants("CareerDescription").Skip(1).First().Value;