ASP.NET XML高级编程（二、XMLReader类和XMLWriter类）

第二章 XMLReader类和XMLWriter类

2.1读取XML：XMLReader

。XMLReader是面向流的，它把XML文档看做是文本数据流。

。XMLReader是一个抽象类。

。XMLReader使用pull模式处理流。

。三个派生类：XMLTextReader、XMLNodeReader和XMLValidatingReader

 XMLTextReader：把XML当做文本流来处理，不需要高速缓存、实体解析或验证，要求XML文档是格式良好的。

 XMLNodeReader：根据XMLNode的实例处理XML。

 XMLValidatingReader：类似于XMLTextReader，但验证DTD，XDR模式或XSD模式。

2.1.1XMLTextReader

   1.构造函数

   XMLTextReader提供了众多构造函数的重载。

   XMLTextReader(),XMLTextReader(Stream),XMLTextReader(String)等

   2.属性

   近30个属性：Name，Item，Value，NoteType等

   3.方法

   近30个方法：Read，GetAttribute，ReadString，MoveToNextAttribute等

2.2编写XML：XMLWriter

   。XMLWriter是一个抽象类

。派生类：XMLTextWriter

XMLWriter使用实例

    class WriteXML
    {
        public void WriteTextXml(string url) {
            XmlTextWriter xmldoc = null;
            try
            {
                xmldoc = new XmlTextWriter(url, System.Text.Encoding.UTF8);
                xmldoc.WriteStartDocument();

                xmldoc.WriteStartElement("info");

                xmldoc.WriteStartElement("OPERATION");
                xmldoc.WriteStartAttribute("ACTION");
                xmldoc.WriteString("ADD");
                xmldoc.WriteEndAttribute();
                
                xmldoc.WriteStartElement("USER-MODULE");

                xmldoc.WriteStartElement("EMPLOYEE-GUID");
                xmldoc.WriteString("employee2");
                xmldoc.WriteEndElement();

                xmldoc.WriteStartElement("DEPARTMENT-GUID");
                xmldoc.WriteString("department2");
                xmldoc.WriteEndElement();

                xmldoc.WriteStartElement("EMPLOYEE_LOGINNAME");
                xmldoc.WriteString("loginname2");
                xmldoc.WriteEndElement();

                xmldoc.WriteStartElement("EMPLOYEE_EMAIL");
                xmldoc.WriteString("email2");
                xmldoc.WriteEndElement();

                xmldoc.WriteStartElement("EMPLOYEE_MOBILE");
                xmldoc.WriteString("mobile2");
                xmldoc.WriteEndElement();

                xmldoc.WriteStartElement("EMPLOYEE_BIRTHDAY");
                xmldoc.WriteString("birthday2");
                xmldoc.WriteEndElement();

                xmldoc.WriteEndElement();
                xmldoc.WriteEndElement();
                xmldoc.WriteEndElement();

            }
            catch (XmlException exc) { }
            finally {
                if (xmldoc != null)
                    xmldoc.Close();
            }
        }
    }

XMLReader使用实例

class ReadXML
    {
        public void XmlTextRead(string url)
        {
            XmlTextReader xmldoc = null;
            try
            {
                xmldoc = new XmlTextReader(url);
                xmldoc.WhitespaceHandling = WhitespaceHandling.None;
                while (xmldoc.Read())
                {
                    switch (xmldoc.NodeType)
                    { 
                        case XmlNodeType.Element:
                            Console.Write("<{0}>", xmldoc.Name);
                            break;
                        case XmlNodeType.Text:
                            Console.Write(xmldoc.Value);
                            break;
                        case XmlNodeType.CDATA:
                            Console.Write("<![CDATA[{0}]]>", xmldoc.Value);
                            break;
                        case XmlNodeType.ProcessingInstruction:
                            Console.Write("<?{0} {1} ?>", xmldoc.Name, xmldoc.Value);
                            break;
                        case XmlNodeType.Comment:
                            Console.Write("<!--{0}-->", xmldoc.Value);
                            break;
                        case XmlNodeType.XmlDeclaration:
                            Console.Write("<?xml version='1.0'?>");
                            break;
                        case XmlNodeType.Document:
                            break;
                        case XmlNodeType.DocumentType:
                            Console.Write("<!DOCTYPE {0} [{1}]", xmldoc.Name, xmldoc.Value);
                            break;
                        case XmlNodeType.EntityReference:
                            Console.Write(xmldoc.Name);
                            break;
                        case XmlNodeType.EndElement:
                            Console.Write("</{0}>", xmldoc.Name);
                            break;
                    }
                }
            }
            catch (XmlException exc)
            {

            }
            finally {
                if (xmldoc != null)
                    xmldoc.Close();
            }


        }
        public void XMLValidatingRead(string url)
        {
            XmlTextReader xmlreader = null;
            XmlValidatingReader xmldoc = null;
            try
            {
                xmlreader = new XmlTextReader(url);
                xmlreader.WhitespaceHandling = WhitespaceHandling.None;
                xmldoc = new XmlValidatingReader(xmlreader);
                while (xmldoc.Read())
                {
                    switch (xmldoc.NodeType)
                    {
                        case XmlNodeType.Element:
                            Console.Write("<{0}>", xmldoc.Name);
                            break;
                        case XmlNodeType.Text:
                            Console.Write(xmldoc.Value);
                            break;
                        case XmlNodeType.CDATA:
                            Console.Write("<![CDATA[{0}]]>", xmldoc.Value);
                            break;
                        case XmlNodeType.ProcessingInstruction:
                            Console.Write("<?{0} {1} ?>", xmldoc.Name, xmldoc.Value);
                            break;
                        case XmlNodeType.Comment:
                            Console.Write("<!--{0}-->", xmldoc.Value);
                            break;
                        case XmlNodeType.XmlDeclaration:
                            Console.Write("<?xml version='1.0'?>");
                            break;
                        case XmlNodeType.Document:
                            break;
                        case XmlNodeType.DocumentType:
                            Console.Write("<!DOCTYPE {0} [{1}]", xmldoc.Name, xmldoc.Value);
                            break;
                        case XmlNodeType.EntityReference:
                            Console.Write(xmldoc.Name);
                            break;
                        case XmlNodeType.EndElement:
                            Console.Write("</{0}>", xmldoc.Name);
                            break;
                    }
                }

            }
            catch (XmlException exc)
            {

            }
            finally {
                if (xmlreader != null)
                    xmlreader.Close();
                if (xmldoc != null)
                    xmldoc.Close();
            }
        }
        public void XMLNodeRead(XmlNode node) {
            XmlNodeReader xmldoc = null;
            try {
                xmldoc = new XmlNodeReader(node);
                while (xmldoc.Read())
                {
                    switch (xmldoc.NodeType)
                    {
                        case XmlNodeType.Element:
                            Console.Write("<{0}>", xmldoc.Name);
                            break;
                        case XmlNodeType.Text:
                            Console.Write(xmldoc.Value);
                            break;
                        case XmlNodeType.CDATA:
                            Console.Write("<![CDATA[{0}]]>", xmldoc.Value);
                            break;
                        case XmlNodeType.ProcessingInstruction:
                            Console.Write("<?{0} {1} ?>", xmldoc.Name, xmldoc.Value);
                            break;
                        case XmlNodeType.Comment:
                            Console.Write("<!--{0}-->", xmldoc.Value);
                            break;
                        case XmlNodeType.XmlDeclaration:
                            Console.Write("<?xml version='1.0'?>");
                            break;
                        case XmlNodeType.Document:
                            break;
                        case XmlNodeType.DocumentType:
                            Console.Write("<!DOCTYPE {0} [{1}]", xmldoc.Name, xmldoc.Value);
                            break;
                        case XmlNodeType.EntityReference:
                            Console.Write(xmldoc.Name);
                            break;
                        case XmlNodeType.EndElement:
                            Console.Write("</{0}>", xmldoc.Name);
                            break;
                    }
                }
            }
            catch (XmlException exc)
            {

            }
            finally
            {
                if (xmldoc != null)
                    xmldoc.Close();
            }
        }
    }

调用

    class Program
    {
        static void Main(string[] args)
        {
            //-----XMLRead---------
            //ReadXML readxml = new ReadXML();
            //readxml.XmlTextRead("F:\\XML\\employee2.xml");
            //readxml.XMLValidatingRead("F:\\XML\\employee2.xml");
            //XmlDocument xml = new XmlDocument();
            //xml.Load("F:\\XML\\employee.xml");
            //readxml.XMLNodeRead(xml.DocumentElement);
            //----XMLWrite------------
            WriteXML writexml = new WriteXML();
            writexml.WriteTextXml("F:\\XML\\employee2.xml");

            Console.ReadLine();
        }
    }

XML文件

<?xml version="1.0" encoding="utf-8"?>
<info>
  <OPERATION ACTION="ADD">
  <USER-MODULE>
    <EMPLOYEE-GUID>employee2</EMPLOYEE-GUID>
    <DEPARTMENT-GUID>department2</DEPARTMENT-GUID>
    <EMPLOYEE_LOGINNAME>loginname2</EMPLOYEE_LOGINNAME>
    <EMPLOYEE_EMAIL>email2</EMPLOYEE_EMAIL>
    <EMPLOYEE_MOBILE>mobile2</EMPLOYEE_MOBILE>
    <EMPLOYEE_BIRTHDAY>birthday2</EMPLOYEE_BIRTHDAY>
  </USER-MODULE>
  </OPERATION>
</info>