Applied XML Programming for Microsoft .NET.pdf - Csbdu.in

Figure 4-14: The code can be used to change the value of the forecolor attribute from blueto black.Adding and Deleting NodesA source XML document can also be easily read and modified by adding or deletingnodes. Let's look at a couple of examples.To add a new node, you simply read until the parent is found and then write an extraset of nodes to the XML writer. Because there might be other nodes with the samename as the parent, use a Boolean guard to ensure that the insertion takes place onlyonce. The following code demonstrates how to proceed:void AddUser(string name, string pswd, string role){XmlTextReadWriter rw;rw = new XmlTextReadWriter(inputFile, outputFile);rw.WriteStartDocument();// Modify the root tag manuallyrw.Writer.WriteStartElement(rw.Reader.LocalName);// Loop through the documentbool mustAddNode = true; // Only oncewhile(rw.Read()){switch(rw.NodeType){case XmlNodeType.Element:rw.Writer.WriteStartElement(rw.Reader.LocalName);if ("Users" == rw.Reader.LocalName && mustAddNode)158