Adding attributes to an XML node

How can I create an xml file dynamically, with the following structure?

<Login>
  <id userName="Tushar" passWord="Tushar">
      <Name>Tushar</Name>
      <Age>24</Age>
  </id>
</Login>

I am not able to create the attributes inside the id tag (i.e. userName="" and passWord="").

I am using C# in a windows application.

Some Important namespace that you might require is

using System.Xml;
using System.IO;

Well id isn't really the root node: Login is.

It should just be a case of specifying the attributes (not tags, btw) using XmlElement.SetAttribute. You haven't specified how you're creating the file though - whether you're using XmlWriter, the DOM, or any other XML API.

If you could give an example of the code you've got which isn't working, that would help a lot. In the meantime, here's some code which creates the file you described:

using System;
using System.Xml;

class Test
{
    static void Main()
    {
        XmlDocument doc = new XmlDocument();
        XmlElement root = doc.CreateElement("Login");
        XmlElement id = doc.CreateElement("id");
        id.SetAttribute("userName", "Tushar");
        id.SetAttribute("passWord", "Tushar");
        XmlElement name = doc.CreateElement("Name");
        name.InnerText = "Tushar";
        XmlElement age = doc.CreateElement("Age");
        age.InnerText = "24";
        
        id.AppendChild(name);
        id.AppendChild(age);
        root.AppendChild(id);
        doc.AppendChild(root);
        
        doc.Save("test.xml");
    }
}

There is also a way to add an attribute to an XmlNode object, that can be useful in some cases.

I found this other method on msdn.microsoft.com.

using System.Xml;

[...]

//Assuming you have an XmlNode called node
XmlNode node;

[...]

//Get the document object
XmlDocument doc = node.OwnerDocument;

//Create a new attribute
XmlAttribute attr = doc.CreateAttribute("attributeName");
attr.Value = "valueOfTheAttribute";

//Add the attribute to the node     
node.Attributes.SetNamedItem(attr);

[...]

The latest and supposedly greatest way to construct the XML is by using LINQ to XML:

using System.Xml.Linq

       var xmlNode =
            new XElement("Login",
                         new XElement("id",
                             new XAttribute("userName", "Tushar"),
                             new XAttribute("password", "Tushar"),
                             new XElement("Name", "Tushar"),
                             new XElement("Age", "24")
                         )
            );
       xmlNode.Save("Tushar.xml");

Supposedly this way of coding should be easier, as the code closely resembles the output (which Jon's example above does not). However, I found that while coding this relatively easy example I was prone to lose my way between the cartload of comma's that you have to navigate among. Visual studio's auto spacing of code does not help either.

You can use the Class XmlAttribute.

Eg:

XmlAttribute attr = xmlDoc.CreateAttribute("userName");
attr.Value = "Tushar";

node.Attributes.Append(attr);

If you serialize the object that you have, you can do something like this by using "System.Xml.Serialization.XmlAttributeAttribute" on every property that you want to be specified as an attribute in your model, which in my opinion is a lot easier:

[System.Xml.Serialization.XmlTypeAttribute(AnonymousType = true)]
public class UserNode
{
    [System.Xml.Serialization.XmlAttributeAttribute()]
    public string userName { get; set; }

    [System.Xml.Serialization.XmlAttributeAttribute()]
    public string passWord { get; set; }

    public int Age { get; set; }
    public string Name { get; set; }         
 }

 public class LoginNode 
 {
    public UserNode id { get; set; }
 }

Then you just serialize to XML an instance of LoginNode called "Login", and that's it!

Here you have a few examples to serialize and object to XML, but I would suggest to create an extension method in order to be reusable for other objects.