How to change a value of element or node in XML file

Maria Bili

14y5.4kC#

Hi all, I have question that I have a xml file, I add it to my Project C# Win Form, Now I want to change a value of 1 node or element, so what I need to do? Please give a guide or link or example project to me reference, thank very much.
Here is demo file xml and picture demo.
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1111
English
2$
222
USA
3$
3333
Singapore
4$

http://i1055.photobucket.com/albums/s505/vn_photo/222.jpg

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Maria Bili14y ago
cherr It very helpfull, I will success. Thank very much.
Vulpes14y ago
That's right.

The code for the button Click eventhandler will be something like this:

using System.Linq;
using System.Xml.Linq;

//...

private void btnChange_Click(object sender, EventArgs e)
{
if (textBox1.Text.Length == 0
{
MessageBox.Show("A node/element ID is needed to make the change");
textBox1.Focus();
return;
}
XElement data = XElement.Load("demo.xml");
XElement searchBook = data.Elements("book").Where(book => book.Element("bookID").Value == textBox1.Text).FirstOrDefault();
if(searchBook != null)
{
searchBook.Element("bookName").Value = textBox3.Text; // insert new value
data.Save("demo.xml");
}
else
{
MessageBox.Show("A node with that ID was not found");
}
}
Maria Bili14y ago
Thank for help. Update my picture demo: http://i1055.photobucket.com/albums/s505/vn_photo/222.jpg
In this I think we a get value from textbox node/element value and transmit it to bookID and after that fill new value of bookName and change ? some one have some opinon ?
Vulpes14y ago
Suppose you want to look for the book node with a bookID of 1111 and change the bookPrice from 2$ to 1$.

This LINQ to XML code should do it:

using System;
using System.Linq;
using System.Xml.Linq;

class Test
{
static void Main()
{
XElement data = XElement.Load("demo.xml");
XElement searchBook = data.Elements("book").Where(book => book.Element("bookID").Value == "1111").FirstOrDefault();
if(searchBook != null)
{
searchBook.Element("bookPrice").Value = "1$";
data.Save("demo.xml");
}
}
}