Read XML file Attributes and Elements using C#

Question

My XML file looks like:

<device name="dev. 1" nodes="16" scenarios="20">
  <package>Pack. 1</package>
  <info>info...</info>
  <picture>pic</picture>
  <nodes>
    <node no="1" name="OUT_1" type="source"/>
    <node no="2" name="OUT_2" type="source"/>
    <node no="3" name="OUT_3" type="source"/>
    <node no="4" name="OUT_4" type="source"/>
  </nodes>
  <scenario name="scenario 1">
    <zth m_node="1" d_node="1" model="table" points="190">
      <data time="1" value="0.1"/>
      <data time="2" value="2"/>
      <data time="2" value="4"/>
    </zth>
    <zth m_node="1" d_node="2" model="table" points="190">
      <data time="1" value="0.3"/>
      <data time="2" value="4"/>
    </zth>
  </scenario>
  <scenario name="scenario 2">
    <zth m_node="1" d_node="1" model="table" points="190">
      <data time="2" value="2"/>
      <data time="1" value="0.3"/>
      <data time="2" value="4"/>
    </zth>
    <zth m_node="1" d_node="2" model="table" points="190">
      <data time="1" value="0.3"/>
      <data time="2" value="4"/>
    </zth>
  </scenario>
</device>

The data I need to read is: The Attribute name from the Element scen from the is in the <data>, I need to get the time and value from the data into arrays but only when the d_node="2" in the <zth>.

This is what I have tried:

    public class Scenario {
        public string name { get; set; }
        public List<string> ZthList { get; set; }
    }

    public class Zth {
        public string m_node { get; set; }
        public string d_node { get; set; }
        public string time { get; set; }
        public string value { get; set; }
    }
    public class XMLReader
    {

        public void xmlReader()
        {

            string currentDir = Environment.CurrentDirectory;
            //getting the directory
            DirectoryInfo directory = new DirectoryInfo(
            Path.GetFullPath(Path.Combine(currentDir, @"..\..\" + @"utils\XML\XMLFile1.xml")));

            XDocument doc = XDocument.Load(Path.Combine(currentDir, @"..\..\" + @"utils\XML\XMLFile1.xml"));
            var scenarios = (from s in doc.Root.Elements("scenario")
                             select new Scenario{
                                 name = (string)s.Attribute("name"), 
                                 ZthList = s.Elements("zth")
                                            .Select(r => new Zth
                                            {
                                                m_node = (string)r.Attribute("m_node"),
                                                d_node = (string)r.Attribute("d_node"),
                                                time = (string)r.Element("data").Attribute("time"),
                                                value = (string)r.Element("data").Attribute("value"),
                                            }).ToList()
                             }).ToList();
            var zth_d_node = scenarios.Where(x => x.ZthList.Any(r => r.d_node == "1")).ToList();
            var s_names = scenarios.Where(x => x.Element("").Value.Equals("name")).toList();

            Console.WriteLine("List: ");
            Console.WriteLine(String.Join(", ", scenarios));
        }
    }

I am getting and error: Severity Code Description Project File Line Suppression State Error CS0029 Cannot implicitly convert type 'System.Collections.Generic.List<project1.utils.Zth>' to 'System.Collections.Generic.List<string>'

Also the data from the time and value is of type double I changed it to string because I was getting a similar error but still it's not working

Maciej Los · Accepted Answer · 2020-07-31 06:58:38Z

1

You need to improve your model to the structure of xml data. See:

public class Scenario {
    public string name { get; set; }
    public List<Zth> ZthList { get; set; }
}

public class Zth {
    public string m_node { get; set; }
    public string d_node { get; set; }
    public List<Data> data { get; set; }
}

public class Data {
    public string t { get; set; }
    public string v { get; set; }
}

Then:

XDocument xdoc = XDocument.Load(...);
List<Scenario> scenarios = xdoc.Descendants("scenario")
    .Select(x=> new Scenario()
        {
            name= x.Attribute("name").Value, 
            ZthList= x.Descendants("zth")
                .Select(y=> new Zth()
                {
                    m_node = y.Attribute("m_node").Value,
                    d_node = y.Attribute("d_node").Value, 
                    data = y.Descendants("data")
                        .Select(z => new Data()
                        {
                            t =  z.Attribute("time").Value,
enter code here

                            v = z.Attribute("value").Value,
                        })
                        .ToList()
                }).ToList()
        }).ToList();

EDIT

If you would like to get only those zth nodes where d_node is equal to 1, you can change this line:

...
ZthList= x.Descendants("zth")
    .Where(n=> n.Attribute("d_node").Value == "1")  //condition was added
    .Select(y=> new Zth()
...

Then result will look like:

edited Jul 31, 2020 at 6:58

answered Jul 30, 2020 at 12:00

Maciej Los

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5 Comments

kristian Over a year ago

Thanks for the hint. I was trying to create a list with all the time values but only when the d_node attribute is 1 in the zth element, how can I save this in another list?

Maciej Los Over a year ago

@kristian, what if the d_node attribute is not equal to 1? data member of zth class will be null! Is it ok?

kristian Over a year ago

If d_node is not 1 the time and value can be ignored, it is relevant only when it's 1.

kristian Over a year ago

When I display the values of the t: Console.WriteLine(String.Join(", ", scenarios.Select(x => x.ZthList.Select(y => y.data.Select(z => z.t))))); I don't get the values, but I get this instead:

System.Linq.Enumerable+WhereSelectListIterator 2[prj.utils.Zth,System.Collections.Generic.IEnumerable 1[System.String]], System.Linq.Enumerable+WhereSelectListIterator 2[prj.utils.Zth,System.Collections.Generic.IEnumerable 1[System.String]]

. I tried to get the names of scenarios this way and it works: Console.WriteLine(String.Join(", ", scenarios.Select(x => x.name))); Did I get something wrong?

Maciej Los Over a year ago

foreach(Scenario sc in scenarios) 	{ 		Console.WriteLine($"---=== {sc.name} ===---"); 		foreach(Zth z in sc.ZthList) 		{ 			Console.WriteLine("times: {0}", string.Join(";", z.data.Select(x=>x.t))); 			Console.WriteLine("values: {0}", string.Join(";", z.data.Select(x=>x.v))); 		} 	}

jdweng · Accepted Answer · 2020-07-30 21:20:57Z

1

I made a bunch of changes. I always recommend to avoid "var" unless it is necessary. You were totally confused because you didn't know the variable types. :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.IO;

namespace ConsoleApplication16
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XMLReader xReader = new XMLReader();
            xReader.xmlReader(FILENAME);
        }
 
    }
    public class Scenario
    {
        public string name { get; set; }
        public List<Zth> ZthList { get; set; }
    }

    public class Zth
    {
        public string m_node { get; set; }
        public string d_node { get; set; }
        public string time { get; set; }
        public string value { get; set; }
    }
    public class XMLReader
    {

        public void xmlReader(string filename)
        {


            XDocument doc = XDocument.Load(filename);
            List<Scenario> scenarios = (from s in doc.Root.Elements("scenario")
                             select new Scenario
                             {
                                 name = (string)s.Attribute("name"),
                                 ZthList = s.Elements("zth")
                                            .Select(r => new Zth()
                                            {
                                                m_node = (string)r.Attribute("m_node"),
                                                d_node = (string)r.Attribute("d_node"),
                                                time = (string)r.Element("data").Attribute("time"),
                                                value = (string)r.Element("data").Attribute("value")
                                            }).ToList()
                             }).ToList();
            List<Scenario> zth_d_node = scenarios.Where(x => x.ZthList.Any(r => r.d_node == "1")).ToList();
            List<Scenario> s_names = scenarios.Where(x => x.name == "name").ToList();

            Console.WriteLine("List: ");
            Console.WriteLine(String.Join(", ", scenarios.Select(x => x.name )));
        }
    }
}

edited Jul 30, 2020 at 21:20

answered Jul 30, 2020 at 11:56

jdweng

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4 Comments

kristian Over a year ago

In this line List<Scenario> zth_d_node = scenarios.Where(x => x.ZthList.Any(r => r.d_node == "1")).ToList(); I was trying to create another list where I "filter" through the zth elements and check if d_node is one, if this is the case I want to save the time values of the element data. How can I save these values in a list, the code that I tried just displays only "true" values, but not the actual data.

jdweng Over a year ago

You are seeing the results of the WHERE (which is either true or false). You need a SELECT after the WHERE to return data.

kristian Over a year ago

Can you be a bit more specific. How can I select the time attribute from data in this case?

jdweng Over a year ago

It is already these. I added a picture to my answer so you can see.

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