覆盖xml文件值

Question

I have a xml file like this

<count>0</count>

Now I wish to overwrite the value 0. How do I do that in c#?

EDIT

<counter>
  <count>0</count>
  <email>
  </email>
</counter>`

This is my XML file I wish to write a value in the email element and also change the value of count element

            XmlDocument doc = new XmlDocument();
            doc.Load(COUNTER);
            foreach (XmlNode node in doc.SelectNodes("count"))
            {
                node.InnerText = (count-1).ToString();
            }
            foreach (XmlNode node in doc.SelectNodes("email"))
            {
                node.InnerText = (count - 1).ToString();
            }
            doc.Save(COUNTER); `

When I do this no values are written to the file

Answer 1

You're not showing us the entire XML, so we cannot really tell you in detail how to do it.

Basically, if your XML file is fairly small, you can load it into an XmlDocument and then search for that <child> node using an XPath expression, and then replace that node's value.

Something like:

// create your XmlDocument
XmlDocument doc = new XmlDocument();

// load the XML from a file on disk - ADAPT to your situation!
doc.Load(@"C:\test.xml");

// search for a node <count>
XmlNode countNode = doc.SelectSingleNode("/counter/count");

// if node is found
if(countNode != null)
{
    // update the node's .InnerText value (the "contents" of the node)    
    countNode.InnerText = "42";

}

// search for a node <email>
XmlNode emailNode = doc.SelectSingleNode("/counter/email");

// if node is found
if(emailNode != null)
{
    // update the node's .InnerText value (the "contents" of the node)    
    emailNode.InnerText = "bob@microsoft.com";
}

// save XmlDocument out to disk again, with the change
doc.Save(@"C:\test_new.xml");

Answer 2

You can read the file in C# using C# XML Classes change the value and then write it back to the file.

You can use ReplaceChild Method for that.

for more info read on XmlDocument and see this Microsoft Example

Answer 3

Using Linq to Xml:

XElement x = XElement.Parse("<myDocument><code>0</code></myDocument>");
x.Descendants().Where(n=>n.Name.LocalName.Equals("code")).ToList().ForEach(n=>n.SetValue("1"));

LINQPad is a great tool for experimenting with this.

Answer 4

您的直接问题是使用doc.SelectNodes("count")而不是doc.GetElementsByTagName("count")