使用XmlWriter写Xml(转)

假定创建了XmlWriter的实例变量xmlWriter，下文中将使用此实例变量写Xml

1.如何使用XmlWriter写Xml文档声明

// WriteStartDocument方法可以接受一个bool参数（表示standalone，是否为独立文档）或者不指定参数standalone保持默认值

xmlWriter.WriteStartDocument(false|true);

注意在使用WriteStartDocument方法后最好调用xmlWrite.WriteEndDocument()方法来关闭所有可能未关闭标签
2.如何使用XmlWriter写xml节点以及属性

//写节点

xmlWriter.WriteStartElement("cat");

//给节点添加属性

xmlWriter.WriteAttributeString("color", "white");

//给节点内部添加文本

xmlWriter.WriteString("I'm a cat");

xmlWriter.WriteEndElement();

或者通过WriteElementString(string,string)方法写xml节点同时写下节点值，如下

//通过WriteElementString可以添加一个节点同时添加节点内容

xmlWriter.WriteElementString("pig", "pig is great");

3.如何写CData

xmlWriter.WriteStartElement("dog");

//写CData

xmlWriter.WriteCData("<strong>dog is dog</strong>");

xmlWriter.WriteEndElement();

4.如何使用XmlWriter添加注释

xmlWriter.WriteComment("this is an example writed by 玉开技术博客 http://www.cnblogs.com/yukaizhao ");

5.如何设置XmlWriter的输出格式，解决输出UTF-16问题
设置xml输出格式，需要通过XmlWriterSettings类，如下代码

XmlWriterSettings settings = new XmlWriterSettings();

//要求缩进

settings.Indent = true;

//注意如果不设置encoding默认将输出utf-16

//注意这儿不能直接用Encoding.UTF8如果用Encoding.UTF8将在输出文本的最前面添加4个字节的非xml内容

settings.Encoding = new UTF8Encoding(false);

//设置换行符

settings.NewLineChars = Environment.NewLine;

完整的代码示例如下：

/*玉开技术博客 http://www.cnblogs.com/yukaizhao */

using System;

using System.Collections.Generic;

using System.Text;

using System.IO;

using System.Xml;

namespace UseXmlWriter

{

    class Program

    {

        static void Main(string[] args)

        {

            using (MemoryStream ms = new MemoryStream())

            {

                XmlWriterSettings settings = new XmlWriterSettings();

                //要求缩进

                settings.Indent = true;

                //注意如果不设置encoding默认将输出utf-16

                //注意这儿不能直接用Encoding.UTF8如果用Encoding.UTF8将在输出文本的最前面添加4个字节的非xml内容

                settings.Encoding = new UTF8Encoding(false);

                //设置换行符

                settings.NewLineChars = Environment.NewLine;

                using (XmlWriter xmlWriter = XmlWriter.Create(ms, settings))

                {

                    //写xml文件开始<?xml version="1.0" encoding="utf-8" ?>

                    xmlWriter.WriteStartDocument(false);

                    //写根节点

                    xmlWriter.WriteStartElement("root");

                    //写字节点

                    xmlWriter.WriteStartElement("cat");

                    //给节点添加属性

                    xmlWriter.WriteAttributeString("color", "white");

                    //给节点内部添加文本

                    xmlWriter.WriteString("I'm a cat");

                    xmlWriter.WriteEndElement();

                    //通过WriteElementString可以添加一个节点同时添加节点内容

                    xmlWriter.WriteElementString("pig", "pig is great");

                    xmlWriter.WriteStartElement("dog");

                    //写CData

                    xmlWriter.WriteCData("<strong>dog is dog</strong>");

                    xmlWriter.WriteEndElement();

                    xmlWriter.WriteComment("this is an example writed by 玉开技术博客 http://www.cnblogs.com/yukaizhao ");

                    xmlWriter.WriteEndElement();

                    xmlWriter.WriteEndDocument();

                }

                //将xml内容输出到控制台中

                string xml = Encoding.UTF8.GetString(ms.ToArray());

                Console.WriteLine(xml);

            }

            Console.Read();

        }

    }

}