Modify XML existing content in C#

Question

Purpose: I plan to Create a XML file with XmlTextWriter and Modify/Update some Existing Content with XmlNode SelectSingleNode(), node.ChildNode[?].InnerText = someting, etc.

After I created the XML file with XmlTextWriter as below.

XmlTextWriter textWriter = new XmlTextWriter("D:\\learning\\cs\\myTest.xml", System.Text.Encoding.UTF8);

I practiced the code below. But failed to save my XML file.

XmlDocument doc = new XmlDocument();
doc.Load("D:\\learning\\cs\\myTest.xml");

XmlNode root = doc.DocumentElement;
XmlNode myNode;

myNode= root.SelectSingleNode("descendant::books");

....

textWriter.Close();

doc.Save("D:\\learning\\cs\\myTest.xml");

I found it is not good to produce like my way. Is there any suggestion about it? I am not clear about the concepts and usage of both XmlTextWriter and XmlNode in the same project. Thank you for reading and replies.

What node are you trying to retrieve? Could you post some of the xml you are using? I am not aware of descendant::books xpath syntax. Also you don't need the XmlTextWriter, just the XmlDocument — Michal Ciechan
– Michal Ciechan, Commented Mar 31, 2010 at 8:12

miguel · Accepted Answer · 2013-10-15 14:25:28Z

37

Well, If you want to update a node in XML, the XmlDocument is fine - you needn't use XmlTextWriter.

XmlDocument doc = new XmlDocument();
doc.Load("D:\\build.xml");
XmlNode root = doc.DocumentElement;
XmlNode myNode = root.SelectSingleNode("descendant::books");
myNode.Value = "blabla";
doc.Save("D:\\build.xml");

edited Oct 15, 2013 at 14:25

miguel

711 gold badge2 silver badges7 bronze badges

answered Mar 31, 2010 at 8:31

jujusharp

5763 silver badges5 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Matthias · Accepted Answer · 2012-06-28 16:01:48Z

27

Using LINQ to xml if you are using framework 3.5

using System.Xml.Linq;

XDocument xmlFile = XDocument.Load("books.xml"); 
var query = from c in xmlFile.Elements("catalog").Elements("book")    
            select c; 
foreach (XElement book in query) 
{
    book.Attribute("attr1").Value = "MyNewValue";
}
xmlFile.Save("books.xml");

edited Jun 28, 2012 at 16:01

Matthias

7,5356 gold badges59 silver badges92 bronze badges

answered Jun 28, 2012 at 11:19

Kashan

97610 silver badges17 bronze badges

Comments

Allen George · Accepted Answer · 2011-06-09 07:05:07Z

Forming a XML file

XmlTextWriter xmlw = new XmlTextWriter(@"C:\WINDOWS\Temp\exm.xml",System.Text.Encoding.UTF8);
xmlw.WriteStartDocument();            
xmlw.WriteStartElement("examtimes");
xmlw.WriteStartElement("Starttime");
xmlw.WriteString(DateTime.Now.AddHours(0).ToString());
xmlw.WriteEndElement();
xmlw.WriteStartElement("Changetime");
xmlw.WriteString(DateTime.Now.AddHours(0).ToString());
xmlw.WriteEndElement();
xmlw.WriteStartElement("Endtime");
xmlw.WriteString(DateTime.Now.AddHours(1).ToString());
xmlw.WriteEndElement();
xmlw.WriteEndElement();
xmlw.WriteEndDocument();  
xmlw.Close();

To edit the Xml nodes use the below code

XmlDocument doc = new XmlDocument(); 
doc.Load(@"C:\WINDOWS\Temp\exm.xml"); 
XmlNode root = doc.DocumentElement["Starttime"]; 
root.FirstChild.InnerText = "First"; 
XmlNode root1 = doc.DocumentElement["Changetime"]; 
root1.FirstChild.InnerText = "Second"; 
doc.Save(@"C:\WINDOWS\Temp\exm.xml");

Try this. It's C# code.

Hans Keﬆing · Accepted Answer · 2010-03-31 08:13:21Z

6

The XmlTextWriter is usually used for generating (not updating) XML content. When you load the xml file into an XmlDocument, you don't need a separate writer.

Just update the node you have selected and .Save() that XmlDocument.

answered Mar 31, 2010 at 8:13

Hans Keﬆing

39.5k10 gold badges84 silver badges119 bronze badges

Collectives™ on Stack Overflow

Modify XML existing content in C#

4 Answers 4

Comments

Comments

Forming a XML file

To edit the Xml nodes use the below code

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Forming a XML file

To edit the Xml nodes use the below code

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related