Question

I have the following XML document named testFix.fix

<WriteFixedWidth Type="extract">
  <Position Start="1" Length="15" Name="Field1" />
  <Position Start="16" Length="8" Name="Field2" />
  <Position Start="24" Length="10" Name="Field3" />
</WriteFixedWidth>

Also, the following code

public void readXML()
{
    XDocument loaded = XDocument.Load(@"testSpec.xml");

    var q = from c in loaded.Descendants("WriteFixedWidth").Elements("Position")
            where c.Parent.Attribute("Type").ToString() == "Extract"
            select new
            {
                 Start = c.Attribute("Start").Value,
                 Length = c.Attribute("Length").Value,
                 Name = c.Attribute("Name").Value
            };

    foreach (var field in q)
        Console.WriteLine("Name is {0}, Start is {1}, Length is {2}", field.Name, field.Start, field.Length);
}

If I remove the where clause I get all of the fields in this XML document as expected. However I would have different “Type” attributes for different operations. How do I filter the data from the parent node? It would be nice to see this as one query rather than building two.

Answer 1

When accessing an attribute, you need to use the Value property, rather than ToString().

var q = from c in loaded.Descendants("WriteFixedWidth").Elements("Position")
            where c.Parent.Attribute("Type").Value == "extract"
            select new
            {
                Start = c.Attribute("Start").Value,
                Length = c.Attribute("Length").Value,
                Name = c.Attribute("Name").Value
            };

(Also note that “extract” is lowercase in your sample, but uppercase in your query)