eXclusiveMinds » XML

Select Top XML Nodes using XPath in C#

eXclusiveMinds — Tue, 01 Dec 2009 23:54:04 +0000

Following exampel demonstrates how can we select Top N nodes from an XML document.
We can use method XmlNode.SelectNodes and Pass XPath expression as a parameter to select Xml Node.

Sample XML file

>
    >James>
    >Wyane>
    >Green>
    >Ballack>
    >Gallass>
    >Rahul>
    >Cashmen>
>

We can get all nodes by using this XPath expression:

 /Names/Name.

We can get only top 5 nodes by using XPath expression:

 /Names/Name[position() <= 5]

Sample Code

XmlDocument doc = new XmlDocument();
doc.LoadXml(str);
XmlNodeList nodes = doc.SelectNodes("/Names/Name[position() <= 5]");
foreach (XmlNode node in nodes)
{
  Console.WriteLine(node.InnerText);
}

OUTPUT:

Frank
Wyane
Green
Ballack
Gallass

Select XML Nodes by Name in C#

eXclusiveMinds — Mon, 02 Feb 2009 00:03:33 +0000

We can use XPath expression for finding nodes in a XML file.
For this we can use following method:
i. XmlNode.SelectNodes.
ii.XmlNode.SelectSingleNode.

Sample XML file

>
    >
        >Steven>
        >Danilo>
    >
    >
        >Milner>
        >Perez>
    >
>

Example Code:

XmlDocument doc = new XmlDocument();
doc.LoadXml(xmlString); 
XmlNodeList nodes = doc.SelectNodes("/Names/Name");
 
//Iterate through node list
foreach (XmlNode node in nodes)
{
	//Get first name
	string firstName = node["FirstName"].InnerText;
	//Get last name  
	string lastName = node["LastName"].InnerText;
	//Pring Name  
	Console.Write("Name: {0} {1}", firstName, lastName);
}

OUTPUT:

Name: Steven Danilo
Name: Milner Perez

Select XML Nodes by Attribute Value in C#

eXclusiveMinds — Thu, 01 Jan 2009 23:59:29 +0000

Following example demonstrates about selecting nodes from XML file by attribute value.
To retrieve list of xml nodes which are selected by XPath expression use method XmlNode.SelectNodes.

Sample XML File

>
     type="M">Rahul>
     type="F">William>
     type="M">Zhang>
>

Following XPath expression gives all nodes:

/Names/Name

Following XPath expression gives only name of males:

/Names/Name[@type='M']

XmlDocument doc = new XmlDocument();
 
//Load xml
xml.LoadXml(str); 
 
XmlNodeList nodes =doc.SelectNodes("/Names/Name[@type='M']");
 
//Iterate through list of nodes
foreach (XmlNode node in nodes)
{
  Console.WriteLine(node.InnerText);
}

The output is:

Rahul
Zhang