Reading multiple child nodes of xml file

Question

I have created an Xml file with example contents as follows:

Answer 1

You could use an XPath approach like so:

XmlNodeList xnl = doc.SelectNodes(string.Format("/Periods/PeriodGroup[@name='{0}']/Period", PG));

Though prefer LINQ to XML for it's readability.

This will return Period node children based on the PeriodGroup name attribute supplied, e.g. HER:

XDocument xml = XDocument.Load(HttpContext.Current.Server.MapPath(FileLoc));

var nodes = (from n in xml.Descendants("Periods")
            where n.Element("PeriodGroup").Attribute("name").Value == "HER"
            select n.Element("PeriodGroup").Descendants().Elements()).ToList();

Results:

<PeriodName>Prehistoric</PeriodName>
<StartDate>-500000</StartDate>
<EndDate>43</EndDate>

<PeriodName>Iron Age</PeriodName>
<StartDate>-800</StartDate>
<EndDate>43</EndDate>

<PeriodName>Roman</PeriodName>
<StartDate>43</StartDate>
<EndDate>410</EndDate>

The query is pretty straightforward

from n in xml.Descendants("Periods")

Will return a collection of the descendant elements for the element Periods. We then use where to filter this collection of nodes based on attribute value:

where n.Element("PeriodGroup").Attribute("name").Value == "HER"

Will then filter down the collection to PeriodGroup elements that have a name attribute with a value of HER

Finally, we select the PeriodGroup element and get it's descendant nodes

select n.Element("PeriodGroup").Descendants().Elements()

EDIT (See comments)

Since the result of this expression is just a query, we use .ToList() to enumerate the collection and return an object containing the values you need. You could also create anonymous types to store the element values for example:

var nodes = (from n in xml.Descendants("Period").
             Where(r => r.Parent.Attribute("name").Value == "HER")
             select new
             {
                  PeriodName = (string)n.Element("PeriodName").Value,
                  StartDate = (string)n.Element("StartDate").Value,
                  EndDate = (string)n.Element("EndDate").Value
             }).ToList();

//Crude demonstration of how you can reference each specific element in the result
//I would recommend using a stringbuilder here..
foreach (var n in nodes)
{
      text += "<br>" + n.PeriodName;
      text += "<br>" + n.StartDate;
      text += "<br>" + n.EndDate;
}

This is what the nodes object will look like after the query has run:

Answer 2

go thru this

 public static void XMLNodeCheck(XmlNode xmlNode)
    {
        if (xmlNode.HasChildNodes)
        {
            foreach (XmlNode node in xmlNode)
            {
                if (node.HasChildNodes)
                {
                    Console.WriteLine(node.Name);
                    if (node.Attributes.Count!=0)
                    {
                        foreach (XmlAttribute att in node.Attributes)
                        {
                            Console.WriteLine("----------" + att.Name + "----------" + att.Value);
                        }
                    }

                    XMLNodeCheck(node);//recursive function 
                }
                else
                {
                    if (!node.Equals(XmlNodeType.Element))
                    {
                        Console.WriteLine(node.InnerText);
                    }

                }
            }
        }
    }

Answer 3

Since the XmlDocument.SelectNodes method actually accepts an XPath expression, you're free to go like this:

XmlNodeList xnl = doc.SelectNodes("/Periods/PeriodGroup[@name='" + PG + "']/Period");
foreach (XmlNode node in xnl) {
    // Every node here is a <Period> child of the relevant <PeriodGroup>.
}

You can learn more on XPath at w3schools.