How to cast XPathEvalute when it can be XElement or XAttribute?

Question

So I have this code:

List prices =
                (from item in xmlDoc.Descendants(shop.DescendantXName)
                 select new PriceDet         


        

Answer 1

Change your XPath expression (shop.TitleXPath) from:

  someXPathExpression

to:

  string(someXPathExpression)

Then you can simplify the code to just:

string result = item.XPathEvaluate(shop.TitleXPath) as string;

---

Complete working example:

using System;
using System.IO;
using System.Xml.Linq;
using System.Xml.XPath;

class TestXPath
{
    static void Main(string[] args)
    {

        string xml1 =
@"
  
 
   element value
 
 
";

        string xml2 =
@"
 
   element value
 
 
";

        TextReader sr = new StringReader(xml1);
        XDocument xdoc = XDocument.Load(sr, LoadOptions.None);

        string result1 = xdoc.XPathEvaluate("string(/*/*/@b | /*/*/b)") as string;

        TextReader sr2 = new StringReader(xml2);
        XDocument xdoc2 = XDocument.Load(sr2, LoadOptions.None);

        string result2 = xdoc2.XPathEvaluate("string(/*/*/@b | /*/*/b)") as string;

        Console.WriteLine(result1);
        Console.WriteLine(result2);


    }
}

When this program is executed, the same XPath expression is applied on two different XML documents and, regardless of the fact that the argument to string() is an attribute the first time and is an element on the second, we get the correct results -- written to the Console:

attribute value
element value