linq查询以解析给定的复杂xml

Question

I have a xml like below with root as rail

        <rail>
        <timetable>
         <trainParts>
              <trainPart id="tp_1" name="1" timetablePeriodRef="ttp_2012_13" categoryRef="cat_Commuter" processStatus="planned" trainNumber="1">
                <operatingPeriodRef ref="Daily" />
                <ocpsTT>
                  <ocpTT ocpType="begin" ocpRef="ocp_SWH">
                    <sectionTT trackInfo="SWH-DM" />
                  </ocpTT>
                  <ocpTT ocpType="stop" ocpRef="ocp_SE">
                     <times arrival="16:16:00" departure="16:18:00" scope="scheduled" />
                    <sectionTT trackInfo="SE-DM" />
                  </ocpTT>
    .
    .
    .
    so on
</ocpsTT>
         </trainPart>
        </trainParts>
        </timetable>
        </rail>

Now like this there are many train numbers whose details I have to parse in one go. I can parse one child and its attributes at a time using linq but i want to parse all the childs and its elements. Say for trainNumer="1" i need to get

categoryRef
    processStatus

    operatingPeriodRef

    ocpType
    ocpRef
    trackInfo

    arrival
    departure

NOTE: In some cases times tag containing departure arrival is not there

I did try to write the code as below:

   public void trainDetails(string trainNumber)
            {

                var xdoc = XDocument.Load("Rail.xml");
                XNamespace ad = "http://www.rail.org/schemas/2009";
                 var train = (from t in xdoc.Root.Elements(ad + "timetable")
                         let d = t.Element(ad + "trainParts").Element("trainPart")
                         where (string)t.Attribute("number") == trainNumber 
                         select new
                         {
                             operatingPeriod=(from s1 in d.Elements(ad+"operatingPeriodRef")
                                              operatingref=(string)s1.Attribute("ref")
                                               }).ToList()
                             }
                         select new
                         {
                            trainOcpsTT= (from s2 in d.Elements(ad + "ocpsTT").Elements(ad+"ocpTT")
                                             select new
                                             {
                                                ocpType=(string)s2.Attribute("ocpType"),
                                                ocpRef=(string)s2.Attribute("ocpRef")
                                              }).ToList()
                             }).FirstOrDefault();

        }
           }

I am unable to frame the query properly.. Is it Possible to get all these in one xml linq query itself?How? If not then which is the proper approach in this case..

Answer 1

Here is my proposal:

public class TrainInfo
{
    public string categoryRef { get; set; }
    public int trainNumber { get; set; }
    public string processStatus { get; set; }
    public string operatingPeriodRef { get; set; }
    public List<ocpsTTs> ocpsTT { get; set; }
}

public struct ocpsTTs
{
    public string ocpType;
    public string ocpRef;
    public string arrival;
    public string departure;
    public string scope;
    public string trackInfo;
}

class Program
{
    static void Main(string[] args)
    {
        TrainInfo ti = ProcessXml(@"XMLFile1.xml", 1);
    }

    static TrainInfo ProcessXml(string xmlfile, int trainnumber)
    {
        TrainInfo retVal;

        try
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(xmlfile);

            XNamespace xns = "http://www.rail.org/schemas/2009";
            XDocument xdoc = System.Xml.Linq.XDocument.Parse(xmlDoc.InnerXml);

            retVal =
                (from c
                 in xdoc.Root.Elements(xns + "timetable").Elements(xns + "trainParts").Elements(xns + "trainPart")
                 where c.Attribute("trainNumber").Value.Equals(trainnumber.ToString())
                 select new TrainInfo
                 {
                     categoryRef = c.Attribute("categoryRef").Value,
                     trainNumber = Int32.Parse(c.Attribute("trainNumber").Value),
                     processStatus = c.Attribute("processStatus").Value,
                     operatingPeriodRef = c.Element(xns + "operatingPeriodRef").Attribute("ref").Value,
                     ocpsTT = (from tt in c.Elements(xns + "ocpsTT").Descendants(xns + "ocpTT")
                               let timeinfo = tt.Elements(xns + "times").Any()
                               select new ocpsTTs
                               {
                                  ocpType = tt.Attribute("ocpType").Value,
                                  ocpRef = tt.Attribute("ocpRef").Value,
                                  arrival = timeinfo ? tt.Element(xns + "times").Attribute("arrival").Value : string.Empty,
                                  departure = timeinfo ? tt.Element(xns + "times").Attribute("departure").Value : string.Empty,
                                  scope = timeinfo ? tt.Element(xns + "times").Attribute("scope").Value : string.Empty,
                                  trackInfo = tt.Element(xns + "sectionTT").Attribute("trackInfo").Value,
                               }).ToList()
                 }).FirstOrDefault();
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
            retVal = null;
        }

        return retVal;
    }
}