C # Two general ways of reading and writing XML

In the application programming interface for XML documents, there are generally two kinds of models: the DOM (Document object method) and the flow model developed by the consortium.

Two variants of the flow model: the "push" model (Simple API for XML) and the "pull" model (. NET in the flow model.

Parsing methods FOR XML:

Pull model

td>

	Push model	dom
	Push model is often called sax , Sax is an event-driven model. It uses a "push" model to raise an event every node it discovers.	. NET in the XML parsing is based on the "pull" model implementation scheme. The pull model pulls the part of interest from the reader when it traverses the document and does not need to raise events. The pull model in. NET implements the	Through the XML Reader (XmlTextReader class). NET implements the DOM model using the XML DOM parser (XMLDocument).
Cons	You must write handlers for these events, which is cumbersome and complex. The document cannot be randomly accessed and modified. The	XmlTextReader class is read-only, forward, and can no longer perform a backward navigation operation in the document.	Requires a one-time load of the entire document into memory, which can cause resource problems for large documents.
Benefits	Do not need to fully load the XML document into memory, it is an efficient API for parsing large XML documents. The	Allows us to access the document in a programmatic way, greatly increasing the flexibility to selectively process nodes, saving only the current node in memory. The XmlTextReader class can verify that the document is well-formed, and if it is not well-formed XML, the class throws a XmlException exception during the read process. The	Allows you to edit and update XML documents, Access data in the document randomly, and use XPath queries.

The. NET Framework supports the XML DOM parser (XmlDocument Class) and the XML Reader (XmlTextReader class) and does not support the SAX parser. However, it is easy to implement all the functions of sax and use it more effectively through the XML reader.

The following classes of XML are organized into the System.Xml namespace:

1. The XmlTextReader---provides fast, one-way, unbuffered access to XML data. (one-way means that you can only read the XML file from the go and not reverse-read)
2. XmlValidatingReader---is used with the XmlTextReader class to provide the ability to validate DTDs, XDR, and XSD schemas.
3. XMLDocument---Follow the standard of the first and two levels of the Document Object Model specification and implement random, cached access to XML data. The first level contains the most basic parts of the DOM, while the second level adds a number of improvements, including increased support for namespaces and cascading charts (CSS).
4. The XmlTextWriter---generates an XML file that follows the 1.0 specification.

C # Two general ways of reading and writing XML