Accessing and Manipulating XML Data in Microsoft .NET Framework

The XML Document Object Model

The XML Document Object Model commonly known as XML DOM is a representation of XML document in memory. The DOM class does the work of reading, writing, and manipulating an XML document. An XML document is a tree-structured consisting of parent and child nodes. In the above example of XML document, <StudentRecords> is the parent node and <Students> is the immediate child node. When more than one nodes are at the same level or they have the same parent node is called as sibling. There are different node types in the XML DOM. They are as under:

The XmlDocument object that is derived from the XmlNode class represents the root node or the document node. The XmlDocument class performs tasks such as loading and saving XML documents and is used to access all the nodes in the document. The XmlDocument object consists of Load, LoadXml and Save methods that loads and saves XML documents. The following code snippet written in Visual Basic .NET shows how to load an XML DOM using Load method:



The following code snippet written in Visual C# .NET shows how to load an XML DOM using Load method:



The XmlReader class and the XmlWriter class derived from the System.Xml namespace are abstract base classes that parse and write XML data from streams or XML documents. In the following sub-headings these classes have been fully illustrated.