XML Programming Technology in the XML _ parsing. NET Framework

Parse XML programming technology under the. NET Framework (reprinted)

I. Preface:
XML is an important part of Microsoft's. NET strategy, and it is the cornerstone of XML Web Services. Therefore, it is very important to master the XML technology under the. NET Framework. This document describes how to use the C # language to read and write XML documents under the. NET Framework. First, I will introduce the XML-related namespaces and important classes in the. NET Framework. Next, I will give examples to help readers better understand the specific methods for reading and writing XML documents.
II. Introduction to XML Namespaces and related classes:
Before proceeding to the XML document operations under the. NET Framework, I think it is necessary to introduce the namespaces related to the XML technology and some important classes in the. NET Framework .. The. NET Framework provides the following namespaces: system. XML, system. XML. schema, system. XML. serialization, system. XML. XPath and system. XML. XSL to include classes related to XML operations.

- The system. xml namespace contains some of the most important XML classes. The most important class is related to the read/write operations of XML documents. These classes include four read-related classes and two write-related classes. They are xmlreader, xmltextreader, xmlvalidatingreader, xmlnodereader, xmlwriter, and xmltextwriter. This article will focus on these classes, because they are the most basic and important classes.

- Xmlreader is a virtual base class that contains methods and attributes for reading XML documents. The read method in this class is a basic method for reading XML documents. It reads nodes in XML documents as streams ). This class also provides more advanced read methods such as readstring, readinnerxml, readouterxml, and readstartelement. In addition to reading XML documents, the xmlreader class also providesProgramProvides navigation functions such as movetoattribute, movetofirstattribute, movetocontent, movetofirstcontent, movetoelement, and movetonextattribute. In the examples described later in this article, we will apply these methods.

- Xmltextreader, xmlnodereader, xmlvalidatingreader, and other classes are inherited from the xmlreader class. Based on their names, we can know that they are used to read text content, read nodes, and read XML Schema (Schemas ).

- The xmlwriter class provides a lot of methods for programmers to write XML documents. It is the base class of the xmltextwriter class. I will provide relevant usage methods in the following examples.

- The xmlnode class is a very important class, which represents a node in the XML document. This node can be the root node of the XML document, which represents the entire XML document. It is the base class of many useful classes, including the class for inserting nodes, deleting nodes, replacing nodes, and completing navigation in XML documents. At the same time, the xmlnode class also provides the programmer with attributes such as the parent node, child node, last child node, node name, and node type. Its three main subclasses include xmldocument, xmldatadocument, and xmldocumentfragment. The xmldocument class represents an XML document. It provides methods and attributes for loading and saving XML documents. These methods include load, loadxml, and save. It also provides the ability to add XML items such as attributes, comments, spaces, elements, and new nodes. The xmldocumentfragment class represents a part of XML documents that can be added to other XML documents. The xmldatadocument class allows programmers to better interoperate with dataset objects in ADO. net.

In addition to the system. in addition to the classes in the XML namespace, The namespace also includes classes such as xmlconvert, xml1_node, and xmlnodelist. However, these classes are not the focus of this article, interested readers may wish to refer to the relevant documentation.

The system. xml. schema namespace contains classes related to the XML schema, including XMLSCHEMA, xmlschemaall, xmlschemaxpath, and xmlschematype.

The system. xml. serialization namespace contains classes related to the serialization and deserialization operations of XML documents. The serialization operations of XML documents can