我如何阅读该XML部分？

Question

I have a link to a online XML file which I read in my application. This is a part of the XML:

<ActueleVertrekTijden>
 <VertrekkendeTrein>
  <RitNummer>4085</RitNummer>
  <VertrekTijd>2014-06-13T22:00:00+0200</VertrekTijd>
  <EindBestemming>Rotterdam Centraal</EindBestemming>
  <TreinSoort>Sprinter</TreinSoort>
  <RouteTekst>A'dam Sloterdijk, Amsterdam C., Duivendrecht</RouteTekst> 
  <Vervoerder>NS</Vervoerder>
  <VertrekSpoor wijziging="false">4</VertrekSpoor>
  <Opmerkingen>
    <Opmerking> Rijdt vandaag niet</Opmerking>
  </Opmerkingen>
 </VertrekkendeTrein>
</ActueleVertrekTijden>

I want to read the "Opmerking" which is listed in "Opmerkingen" and is standing in "VertrekkendeTrein":

<Opmerkingen>
    <Opmerking> Rijdt vandaag niet</Opmerking>
</Opmerkingen>

The problem is that it is not always there, it will depend of the situation.

I can read the other parts like "RitNummer" and "Vervoerder", and i use the following code to do that:

string urlo = "THEWEBSITE";
            string resultje = HttpGeto(urlo);

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(resultje);
XmlNodeList nodeList = xmlDoc.SelectNodes("ActueleVertrekTijden/VertrekkendeTrein/*");



       foreach (XmlNode nodelist2 in nodeList)
           {//14  101517
            //int i = 0;//if (i == 0) { i++; }
               if (i < 1) //1
               {

                 switch (nodelist2.Name)
                  {
                    case "VertrekTijd": string kuttijd1 = (nodelist2.InnerText);
                    var res1 = Regex.Match(kuttijd1, @"\d{1,2}:\d{1,2}").Value;
                    lblv1.Text = Convert.ToString(res1); break;
                    case "VertrekVertragingTekst": var tobiasisnietvantexel1 = (nodelist2.InnerText); if (tobiasisnietvantexel1 == null) {} else{ ververt1.Text = tobiasisnietvantexel1; ververt1.Visible = true; vertpic1.Visible = true; logo1.Top -= 9; lblts1.Top -= 9; } break;
                    case "EindBestemming": string vertrek1 = (nodelist2.InnerText); if (vertrek1 == "Uitgeest") { lblvia1.Text = "Krommenie-Ass"; } lblbs1.Text = vertrek1; break;
                    case "TreinSoort": lblts1.Text = (nodelist2.InnerText); break;
                    case "RouteTekst": lblvia1.Text = (nodelist2.InnerText); break;
                    case "VertrekSpoor": lbls1.Text = (nodelist2.InnerText); i++;  break;


                   }


                }
           }

I tried a lot like:

case "Opmerking": var texeliseeneiland1 

and

case "Opmerkingen/Opmerking": var texeliseeneiland1 

Is there a way i can make a case for "Opmerking"?

Thanks!

Answer 1

Simplest and not the most elegant solution is to extract child nodes from the "Opmerkingen" node list:

case "Opmerkingen":
{
    XmlNodeList nodeListOp = nodelist2.SelectNodes("Opmerking");
    foreach (XmlNode node in nodeListOp)
    {
        if (node.Name == "Opmerking")
        {
            // your "Opmerking" stuff here
        }
    }
    break;
}

Answer 2

You might try turning the XML node list/set into a queryable data structure, and use System.Linq to see if it contains and Opmerking. Although that's my preference because I've been doing a lot of database queries.

In your situation, with your switch statement and many cases, you might try the following:

In the case for "Opmerkingen" nest another case to see if it has a child node "Opmerking", and than do something with that "Opmerking" node. Or have the case "Opmerkingen" call a function to do something with the "opmerking" node.

Edit for an example:

   foreach (XmlNode nodelist2 in nodeList)
       {//14  101517
        //int i = 0;//if (i == 0) { i++; }
           if (i < 1) //1
           {

             switch (nodelist2.Name)
              {
                case "VertrekTijd": string kuttijd1 = (nodelist2.InnerText);
                var res1 = Regex.Match(kuttijd1, @"\d{1,2}:\d{1,2}").Value;
                lblv1.Text = Convert.ToString(res1); break;
                case "VertrekVertragingTekst": var tobiasisnietvantexel1 = (nodelist2.InnerText); if (tobiasisnietvantexel1 == null) {} else{ ververt1.Text = tobiasisnietvantexel1; ververt1.Visible = true; vertpic1.Visible = true; logo1.Top -= 9; lblts1.Top -= 9; } break;
                case "EindBestemming": string vertrek1 = (nodelist2.InnerText); if (vertrek1 == "Uitgeest") { lblvia1.Text = "Krommenie-Ass"; } lblbs1.Text = vertrek1; break;
                case "TreinSoort": lblts1.Text = (nodelist2.InnerText); break;
                case "RouteTekst": lblvia1.Text = (nodelist2.InnerText); break;
                case "VertrekSpoor": lbls1.Text = (nodelist2.InnerText); i++;  break;

                //Here's the case you might try adding
                case "Opmerkingen": var SomeVar = OpmerkingenMethod(nodelist2); break; 
                //or do something else that you want to do, instead of breaking,
                //I do not know what you want to do with Opmerking when you get it
                // so I just had the function output into another variable.
               }


            }
       }

Here's an example of a method you might use in the case of Opmerkingen, so that you can get to Opmerking and do something with that. Again, I don't know what exactly you want to do iw

private string OpmerkingenMethod(XmlNode node)
{
     //Do something with XmlNode Opmerkingen
     var something = node.Name  //Or whatever you want from Opmerkingen node
     return something
}

This might be more along the lines of what you want, again I haven't tested the code, this is just to demonstrate the code that does what you want.

private string OpmerkingenMethod(XmlNode node)
{
     //Do something with XmlNode Opmerkingen
     var child = node.FistChild;

     if(child.name == "Opmerking") 
     {
          return child.InnerText // or whatever you want
     }
     else { return "" ; }

}

you could call this method in the case of Opmerkingen and check the output, if it's what you want, break the switch statement, if it's not what you want (because there's no opmerking or something) you could continue to the next case, or break to go to the next node in nodelist. Again, the point is to call the method when you see Opmerkingen so that you can then get the node or value that's inside Opmerkingen