xPath Document, Navigator, Expression.

Read BookStore.xml using XPath Iterator.



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

namespace BookStoreApp
{
class Program
{
static void Main(string[] args)
{

Program bk = new Program();

bk.DisplayBooksLess10();

bk.DisplayNovel();
bk.DisplayFirstNameAInIt();
bk.DisplayNovelOverSix();

//Add the new book
bk.AddBookNode();
}


public void DisplayFirstNameAInIt()
{
Console.WriteLine("A char in Author's first name");

XPathNavigator nav;
XPathDocument docNav;
XPathNodeIterator NodeIter;

//String strExpression;





// Open the XML.
docNav = new XPathDocument("BookStore.xml");

nav = docNav.CreateNavigator();

XmlNamespaceManager nsmgr = new XmlNamespaceManager(nav.NameTable);
nsmgr.AddNamespace("b", "http://www.contoso.com/books");
nsmgr.AddNamespace("g", "http://www.contoso.com/genre");
nsmgr.AddNamespace("a", "http://www.contoso.com/author");

XPathExpression expr = nav.Compile("/b:bookstore/b:book[contains(a:author/a:first-name,'a')]/b:title");
expr.SetContext(nsmgr);


//strExpression = "/bookstore/book/title[../price>10.00]";

NodeIter = nav.Select(expr);

while (NodeIter.MoveNext())
{

Console.WriteLine("Book Title: {0}", NodeIter.Current.Value);
};
Console.WriteLine("\n" + "Press ENTER key....");
Console.ReadLine();


}

public void DisplayNovelOverSix()
{
Console.WriteLine("Average of Novels over £6");

XPathNavigator nav;
XPathDocument docNav;
XPathNodeIterator NodeIter;
//String strExpression;





// Open the XML.
docNav = new XPathDocument("BookStore.xml");

nav = docNav.CreateNavigator();

XmlNamespaceManager nsmgr = new XmlNamespaceManager(nav.NameTable);
nsmgr.AddNamespace("b", "http://www.contoso.com/books");
nsmgr.AddNamespace("g", "http://www.contoso.com/genre");
nsmgr.AddNamespace("a", "http://www.contoso.com/author");

//XPathExpression expr = nav.Compile("/b:bookstore/b:book[@g:genre='novel' and b:price>6.00]/b:title");
//expr.SetContext(nsmgr);


string avg = nav.Evaluate("sum(descendant::b:bookstore/b:book[@g:genre='novel' and b:price>6.00]/b:price)" +
" div count(descendant::b:bookstore/b:book[@g:genre='novel' and b:price>6.00])", nsmgr).ToString();




Console.WriteLine("Books Average Price: {0}", avg);
Console.WriteLine("\n" + "Press ENTER key....");
Console.ReadLine();


}

public void DisplayNovel()
{
Console.WriteLine("Display Novels");

XPathNavigator nav;
XPathDocument docNav;
XPathNodeIterator NodeIter;
//String strExpression;





// Open the XML.
docNav = new XPathDocument("BookStore.xml");

nav = docNav.CreateNavigator();

XmlNamespaceManager nsmgr = new XmlNamespaceManager(nav.NameTable);
nsmgr.AddNamespace("b", "http://www.contoso.com/books");
nsmgr.AddNamespace("g", "http://www.contoso.com/genre");

XPathExpression expr = nav.Compile("/b:bookstore/b:book[@g:genre='novel']/b:title");
expr.SetContext(nsmgr);


//strExpression = "/bookstore/book/title[../price>10.00]";

NodeIter = nav.Select(expr);

while (NodeIter.MoveNext())
{

Console.WriteLine("Book Title: {0}", NodeIter.Current.Value);
};
Console.WriteLine("\n" + "Press ENTER key....");
Console.ReadLine();


}
public void DisplayBooksLess10()
{
Console.WriteLine("Books less than £10");

XPathNavigator nav;
XPathDocument docNav;
XPathNodeIterator NodeIter;
//String strExpression;





// Open the XML.
docNav = new XPathDocument("BookStore.xml");

nav = docNav.CreateNavigator();

XmlNamespaceManager nsmgr = new XmlNamespaceManager(nav.NameTable);
nsmgr.AddNamespace("b", "http://www.contoso.com/books");
nsmgr.AddNamespace("g", "http://www.contoso.com/genre");
nsmgr.AddNamespace("a", "http://www.contoso.com/author");

XPathExpression expr = nav.Compile("/b:bookstore/b:book[b:price<'10.00']/b:title");
expr.SetContext(nsmgr);


//strExpression = "/bookstore/book/title[../price>10.00]";

NodeIter = nav.Select(expr);

while (NodeIter.MoveNext())
{

Console.WriteLine("Book Title: {0}", NodeIter.Current.Value);
};
Console.WriteLine("\n" + "Press ENTER key....");
Console.ReadLine();


}

public void AddBookNode()
{

Console.WriteLine("Adding a book node to existing xml");

XmlDocument myDoc = new XmlDocument();
myDoc.Load("BookStore.xml");
XmlNode root = myDoc.DocumentElement;
XmlNamespaceManager nsmgr = new XmlNamespaceManager(myDoc.NameTable);
nsmgr.AddNamespace("b", "http://www.contoso.com/books");
nsmgr.AddNamespace("g", "http://www.contoso.com/genre");
nsmgr.AddNamespace("a", "http://www.contoso.com/author");
// Create a Book element and populate its attributes
System.Xml.XmlElement newBook = myDoc.CreateElement("book", "http://www.contoso.com/books");
//create the three attributes to hold the values
newBook.SetAttribute("genre", "http://www.contoso.com/genre", "novel");
newBook.SetAttribute("publicationdate", "2011-06-14");
newBook.SetAttribute("ISBN", "1-1245-45455");
System.Xml.XmlElement xeTitle = myDoc.CreateElement("title");
xeTitle.InnerText = "MyBook";
// Insert the new element under the node we created
newBook.AppendChild(xeTitle);
System.Xml.XmlElement myAuthor = myDoc.CreateElement("author");
myAuthor.SetAttribute("xmlns", ("http://www.contoso.com/author"));
System.Xml.XmlElement xeFirstname = myDoc.CreateElement("first-name");
xeFirstname.InnerText = "Siraj";
myAuthor.AppendChild(xeFirstname);
System.Xml.XmlElement xeLastname = myDoc.CreateElement("last-name");
xeLastname.InnerText = "Zarook";
myAuthor.AppendChild(xeLastname);
newBook.AppendChild(myAuthor);
// Price
System.Xml.XmlElement xePrice = myDoc.CreateElement("price");
xePrice.InnerText = "1.47";
// Insert the new element under the node we created
newBook.AppendChild(xePrice);
//append the whole node to file
myDoc.DocumentElement.AppendChild(newBook);
myDoc.Save("BookStoreModified.xml");

Console.WriteLine("File BookStoreModified.xml has been created in the application folder"
+ "\n" + "Press ENTER key..");

Console.ReadLine();
}

}
}

XML with asp.net - Simple work

XmlDataSource.XPath Property

Walkthrough: Creating a Web Page to Display XML Data

Read XML File

'xmldoc.Load("C:\Siraj\" & "Response_Test.xml")

'Dim Response_data As String

Dim nsmRequest As New XmlNamespaceManager(xmldoc.NameTable)

nsmRequest.AddNamespace("soapenv", "http://schemas.xmlsoap.org/soap/envelope/")
nsmRequest.AddNamespace("oug", "http://webcomponent.components.oug.osgi.scorex.com/")

'XmlElement root = xmldoc.DocumentElement;
Dim nodes As XmlNodeList = xmldoc.DocumentElement.SelectNodes("//oug:MyWSResponse/items/item", nsmRequest)
' you cannot use prefix with NameSpaceMng
'XmlNodeList nodes = xmldoc.DocumentElement.SelectNodes("//myWSResponse/items");
For Each node As XmlNode In nodes
'Response.Write(node.InnerText)
If node.Name.ToUpper = "ITEM" And node.InnerText.ToUpper = "MY_RC" Then
'
If node.NextSibling.InnerText = "0" Then
SubmissionSuccess = True
End If
ElseIf node.Name.ToUpper = "ITEM" And node.InnerText.ToUpper = "RC_DESC" Then ' useful when WF_RC IS <> 0
RC_DESC = node.NextSibling.InnerText

ElseIf node.Name.ToUpper = "ITEM" And node.InnerText.ToUpper = "CODE" Then ' useful when WF_RC IS <> 0
' This could be a lookup table - ALL SYS???? Error codes
Return_Code = node.NextSibling.InnerText
If Return_Code <> "0" Then
SubmissionSuccess = False
Exit For ' If error during submission data tag will not be used
End If
ElseIf node.Name.ToUpper = "ITEM" And node.InnerText.ToUpper = "DATA" Then
Response_Data = node.NextSibling.InnerText
End If
Next



*******Select Single Node


thisNode = xmlResponseData.DocumentElement.SelectSingleNode("//OUTPUT/MY_NUM")
If Not thisNode Is Nothing Then
AppNum = thisNode.InnerText
End If

Reading XML Files with ASP.NET

This is full article from Faizal Khan.

Reading XML Files with ASP.NET

We can bind an XML file to a list/combo box control.

Read This

Populate with ListArray and Hashtable/

Read This

Display XmlDataSource. using XPath ASP.Net

The following code example demonstrates how to use an XmlDataSource control with a templated Repeater control to display XML data that has been filtered using an XPath expression.

MSDN Source

**************

Walkthrough: Creating a Web Page to Display XML Data

Displaying XML Data in a List Control

Walkthrough: Displaying and Tracking Advertisements with the AdRotator Control

Creating Advertisements

How to navigate XML with the XPathNavigator class by using VB / C#

by Microsoft. simple sample

How to get it done in C#


Another good example from Microsoft.

create xml doc in vb.net

Public Function next_ten_dates(ByVal startDate As Date) As String

Dim xDoc As New XmlDocument
Dim xNode As XmlElement
Dim newAtt As XmlAttribute
Dim xDocRoot As XmlElement = xDoc.CreateElement("dates")
xDoc.AppendChild(xDocRoot)
For i As Integer = 0 To 10
Dim xdate As XmlNode = xDoc.CreateElement("date")
xdate.InnerText = getJapaneseDate(startDate.AddDays(i))
newAtt = xDoc.CreateAttribute("daysinmonth")
Dim datesinmonth = startDate.DaysInMonth(startDate.Year, _
startDate.Month)
newAtt.Value = datesinmonth.ToString()
xdate.Attributes.Append(newAtt)
xDocRoot.AppendChild(xdate)

Next
Dim XMLString As String = ""
Dim sw As New StringWriter()
Dim xw As New XmlTextWriter(sw)
xDoc.WriteTo(xw)
XMLString = sw.ToString()
next_ten_dates = XMLString

End Function

XPath

XPath (wild cards)

Using XPath with VB.Net