基于C#中XmlWriter寫入Xml的深入分析

2020-01-24 03:18:17

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假定創建了XmlWriter的實例變量xmlWriter，下文中將使用此實例變量寫Xml
1.如何使用XmlWriter寫Xml文檔聲明

// WriteStartDocument方法可以接受一個bool參數（表示standalone，是否為獨立文檔）或者不指定參數standalone保持默認值 
xmlWriter.WriteStartDocument(false|true); 

注意在使用WriteStartDocument方法后最好調用xmlWrite.WriteEndDocument()方法來關閉所有可能未關閉標簽
2.如何使用XmlWriter寫xml節點以及屬性

復制代碼代碼如下:

//寫節點 
xmlWriter.WriteStartElement("cat"); 
//給節點添加屬性 
xmlWriter.WriteAttributeString("color", "white"); 
//給節點內部添加文本 
xmlWriter.WriteString("I'm a cat"); 
xmlWriter.WriteEndElement(); 

或者通過WriteElementString(string,string)方法寫xml節點同時寫下節點值，如下

復制代碼代碼如下:

//通過WriteElementString可以添加一個節點同時添加節點內容 
xmlWriter.WriteElementString("pig", "pig is great"); 

3.如何寫CData

復制代碼代碼如下:

xmlWriter.WriteStartElement("dog"); 
//寫CData 
xmlWriter.WriteCData("<strong>dog is dog</strong>"); 
xmlWriter.WriteEndElement(); 

4.如何使用XmlWriter添加注釋

復制代碼代碼如下:

xmlWriter.WriteComment("this is an example writed by //www.5lwq4hdr.cn ");

5.如何設置XmlWriter的輸出格式，解決輸出UTF-16問題
設置xml輸出格式，需要通過XmlWriterSettings類，如下代碼

復制代碼代碼如下:

XmlWriterSettings settings = new XmlWriterSettings(); 
//要求縮進 
settings.Indent = true; 
//注意如果不設置encoding默認將輸出utf-16 
//注意這兒不能直接用Encoding.UTF8如果用Encoding.UTF8將在輸出文本的最前面添加4個字節的非xml內容 
settings.Encoding = new UTF8Encoding(false); 

//設置換行符 
settings.NewLineChars = Environment.NewLine;

完整的代碼示例如下：

復制代碼代碼如下:

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(); 
                //要求縮進 
                settings.Indent = true; 
                //注意如果不設置encoding默認將輸出utf-16 
                //注意這兒不能直接用Encoding.UTF8如果用Encoding.UTF8將在輸出文本的最前面添加4個字節的非xml內容 
                settings.Encoding = new UTF8Encoding(false); 

                //設置換行符 
                settings.NewLineChars = Environment.NewLine; 

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

                    //寫xml文件開始<?xml version="1.0" encoding="utf-8" ?> 
                    xmlWriter.WriteStartDocument(false); 
                    //寫根節點 
                    xmlWriter.WriteStartElement("root"); 
                    //寫字節點 
                    xmlWriter.WriteStartElement("cat"); 
                    //給節點添加屬性 
                    xmlWriter.WriteAttributeString("color", "white"); 
                    //給節點內部添加文本 
                    xmlWriter.WriteString("I'm a cat"); 
                    xmlWriter.WriteEndElement(); 

  
                    //通過WriteElementString可以添加一個節點同時添加節點內容 
                    xmlWriter.WriteElementString("pig", "pig is great"); 

  
                    xmlWriter.WriteStartElement("dog"); 
                    //寫CData 
                    xmlWriter.WriteCData("<strong>dog is dog</strong>"); 
                    xmlWriter.WriteEndElement(); 

                    xmlWriter.WriteComment("this is an example writed by  //www.5lwq4hdr.cn "); 

                    xmlWriter.WriteEndElement(); 
                    xmlWriter.WriteEndDocument(); 

                } 

                //將xml內容輸出到控制臺中 
                string xml = Encoding.UTF8.GetString(ms.ToArray()); 
                Console.WriteLine(xml); 
            } 
            Console.Read(); 

        } 
    } 
}