Modify XML existing content in C#
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.SelectSingleNo开发者_如何学编程de("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.
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");
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");
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.
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.
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