Question

I am probably missing something obvious, but I am getting a ‘Object reference not set to an instance of an object’ null error in my Linq to xml query.

Here is a sample of the xml

<airport>
  <station>
  <city>Rutland</city>
  <state>VT</state>
  <country>US</country>
  <icao>KRUT</icao>
  <lat>43.52999878</lat>
  <lon>-72.94999695</lon>
  </station>
</airport>

and here is my query

XDocument geoLocation = XDocument.Load("myTestGeo.xml");

            var currLocation = from geo in geoLocation.Descendants("airport")
                              select new
                              {
                                  City = geo.Element("city").Value,
                                  State = geo.Element("state").Value,
                                  Country = geo.Element("country").Value,
                                  Station = geo.Element("icao").Value
                                  Lat = geo.Element("lat").Value,
                                  Lon = geo.Element("lon").Value
                              };

I have been looking at this all day and tried lots of things, but no luck. Can someone help this dense programmer?

Answer 1

city and all the other values are inside station and are not direct descendants of airport.

Perhaps some indentation sheds some light into the issue.

<airport>
  <station>
    <city>Rutland</city>
    <state>VT</state>
    <country>US</country>
    <icao>KRUT</icao>
    <lat>43.52999878</lat>
    <lon>-72.94999695</lon>
  </station>
</airport>

This would probably work:

XDocument geoLocation = XDocument.Load("myTestGeo.xml");

var currLocation = from geo in geoLocation.Descendants("station")
                  select new
                  {
                      City = geo.Element("city").Value,
                      State = geo.Element("state").Value,
                      Country = geo.Element("country").Value,
                      Station = geo.Element("icao").Value
                      Lat = geo.Element("lat").Value,
                      Lon = geo.Element("lon").Value
                  };