C# 关于XML的内容

1、简单介绍

using System.Xml;
//初始化一个xml实例
XmlDocument xml=new XmlDocument();

//导入指定xml文件
xml.Load(path);
xml.Load(HttpContext.Current.Server.MapPath("~/file/bookstore.xml"));

//指定一个节点
XmlNode root=xml.SelectSingleNode("/root");

//获取节点下所有直接子节点
XmlNodeList childlist=root.ChildNodes;

//判断该节点下是否有子节点
root.HasChildNodes;

//获取同名同级节点集合
XmlNodeList nodelist=xml.SelectNodes("/Root/News");

//生成一个新节点
XmlElement node=xml.CreateElement("News");

//将节点加到指定节点下，作为其子节点
root.AppendChild(node);

//将节点加到指定节点下某个子节点前
root.InsertBefore(node,root.ChildeNodes[i]);

//为指定节点的新建属性并赋值
node.SetAttribute("id","11111");

//为指定节点添加子节点
root.AppendChild(node);

//获取指定节点的指定属性值
string id=node.Attributes["id"].Value;

//获取指定节点中的文本
string content=node.InnerText;

//保存XML文件
string path=Server.MapPath("~/file/bookstore.xml");
xml.Save(path);
//or use :xml.Save(HttpContext.Current.Server.MapPath("~/file/bookstore.xml"));

---------------------------------------------------------------------------------------------------

二、具体实例

在C#.net中如何操作XML
需要添加的命名空间：
using System.Xml;

1、创建到服务器同名目录下的xml文件：

方法一：

XmlDocument xmldoc;
            XmlNode xmlnode;
            XmlElement xmlelem;
            xmldoc = new XmlDocument();
            //加入XML的声明段落,<?xml version="1.0" encoding="gb2312"?>
            XmlDeclaration xmldecl;
            xmldecl = xmldoc.CreateXmlDeclaration("1.0", "gb2312", null);
            xmldoc.AppendChild(xmldecl);
            //加入一个根元素
            xmlelem = xmldoc.CreateElement("", "Employees", "");
            xmldoc.AppendChild(xmlelem);
            //加入另外一个元素
            for (int i = 1; i < 3; i++)
            {
                XmlNode root = xmldoc.SelectSingleNode("Employees");//查找<Employees>
                XmlElement xe1 = xmldoc.CreateElement("Node");//创建一个<Node>节点
                xe1.SetAttribute("genre", "李赞红");//设置该节点genre属性
                xe1.SetAttribute("ISBN", "2-3631-4");//设置该节点ISBN属性
                XmlElement xesub1 = xmldoc.CreateElement("title");
                xesub1.InnerText = "CS从入门到精通";//设置文本节点
                xe1.AppendChild(xesub1);//添加到<Node>节点中
                XmlElement xesub2 = xmldoc.CreateElement("author");
                xesub2.InnerText = "候捷";
                xe1.AppendChild(xesub2);
                XmlElement xesub3 = xmldoc.CreateElement("price");
                xesub3.InnerText = "58.3";
                xe1.AppendChild(xesub3);
                root.AppendChild(xe1);//添加到<Employees>节点中
            }
            //保存创建好的XML文档
            xmldoc.Save("data.xml");

XmlDocument xmldoc; XmlNode xmlnode; XmlElement xmlelem; xmldoc = new XmlDocument(); //加入XML的声明段落,<?xml version="1.0" encoding="gb2312"?> XmlDeclaration xmldecl; xmldecl = xmldoc.CreateXmlDeclaration("1.0", "gb2312", null); xmldoc.AppendChild(xmldecl); //加入一个根元素 xmlelem = xmldoc.CreateElement("", "Employees", ""); xmldoc.AppendChild(xmlelem); //加入另外一个元素 for (int i = 1; i < 3; i++) { XmlNode root = xmldoc.SelectSingleNode("Employees");//查找<Employees> XmlElement xe1 = xmldoc.CreateElement("Node");//创建一个<Node>节点 xe1.SetAttribute("genre", "李赞红");//设置该节点genre属性 xe1.SetAttribute("ISBN", "2-3631-4");//设置该节点ISBN属性 XmlElement xesub1 = xmldoc.CreateElement("title"); xesub1.InnerText = "CS从入门到精通";//设置文本节点 xe1.AppendChild(xesub1);//添加到<Node>节点中 XmlElement xesub2 = xmldoc.CreateElement("author"); xesub2.InnerText = "候捷"; xe1.AppendChild(xesub2); XmlElement xesub3 = xmldoc.CreateElement("price"); xesub3.InnerText = "58.3"; xe1.AppendChild(xesub3); root.AppendChild(xe1);//添加到<Employees>节点中 } //保存创建好的XML文档 xmldoc.Save("data.xml"); 

方法二：

XmlTextWriter xmlWriter;
            string strFilename = "data1.xml";
            xmlWriter = new XmlTextWriter(strFilename, Encoding.Default);//创建一个xml文档
            xmlWriter.Formatting = Formatting.Indented;
            xmlWriter.WriteStartDocument();
            xmlWriter.WriteStartElement("Employees");
            xmlWriter.WriteStartElement("Node");
            xmlWriter.WriteAttributeString("genre", "李赞红");
            xmlWriter.WriteAttributeString("ISBN", "2-3631-4");
            xmlWriter.WriteStartElement("title");
            xmlWriter.WriteString("CS从入门到精通");
            xmlWriter.WriteEndElement();
            xmlWriter.WriteStartElement("author");
            xmlWriter.WriteString("候捷");
            xmlWriter.WriteEndElement();
            xmlWriter.WriteStartElement("price");
            xmlWriter.WriteString("58.3");
            xmlWriter.WriteEndElement();
            xmlWriter.WriteEndElement();
            xmlWriter.Close();

XmlTextWriter xmlWriter; string strFilename = "data1.xml"; xmlWriter = new XmlTextWriter(strFilename, Encoding.Default);//创建一个xml文档 xmlWriter.Formatting = Formatting.Indented; xmlWriter.WriteStartDocument(); xmlWriter.WriteStartElement("Employees"); xmlWriter.WriteStartElement("Node"); xmlWriter.WriteAttributeString("genre", "李赞红"); xmlWriter.WriteAttributeString("ISBN", "2-3631-4"); xmlWriter.WriteStartElement("title"); xmlWriter.WriteString("CS从入门到精通"); xmlWriter.WriteEndElement(); xmlWriter.WriteStartElement("author"); xmlWriter.WriteString("候捷"); xmlWriter.WriteEndElement(); xmlWriter.WriteStartElement("price"); xmlWriter.WriteString("58.3"); xmlWriter.WriteEndElement(); xmlWriter.WriteEndElement(); xmlWriter.Close();

2、添加一个结点

XmlDocument xmlDoc = new XmlDocument();
           xmlDoc.Load("data.xml");
           XmlNode root = xmlDoc.SelectSingleNode("Employees");//查找<Employees>
           XmlElement xe1 = xmlDoc.CreateElement("Node");//创建一个<Node>节点
           xe1.SetAttribute("genre", "张三");//设置该节点genre属性
           xe1.SetAttribute("ISBN", "1-1111-1");//设置该节点ISBN属性
           XmlElement xesub1 = xmlDoc.CreateElement("title");
           xesub1.InnerText = "C#入门帮助";//设置文本节点
           xe1.AppendChild(xesub1);//添加到<Node>节点中
           XmlElement xesub2 = xmlDoc.CreateElement("author");
           xesub2.InnerText = "高手";
           xe1.AppendChild(xesub2);
           XmlElement xesub3 = xmlDoc.CreateElement("price");
           xesub3.InnerText = "158.3";
           xe1.AppendChild(xesub3);
           root.AppendChild(xe1);//添加到<Employees>节点中
           xmlDoc.Save("data.xml");

XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load("data.xml"); XmlNode root = xmlDoc.SelectSingleNode("Employees");//查找<Employees> XmlElement xe1 = xmlDoc.CreateElement("Node");//创建一个<Node>节点 xe1.SetAttribute("genre", "张三");//设置该节点genre属性 xe1.SetAttribute("ISBN", "1-1111-1");//设置该节点ISBN属性 XmlElement xesub1 = xmlDoc.CreateElement("title"); xesub1.InnerText = "C#入门帮助";//设置文本节点 xe1.AppendChild(xesub1);//添加到<Node>节点中 XmlElement xesub2 = xmlDoc.CreateElement("author"); xesub2.InnerText = "高手"; xe1.AppendChild(xesub2); XmlElement xesub3 = xmlDoc.CreateElement("price"); xesub3.InnerText = "158.3"; xe1.AppendChild(xesub3); root.AppendChild(xe1);//添加到<Employees>节点中 xmlDoc.Save("data.xml");

3、修改结点的值（属性和子结点）

XmlDocument xmlDoc = new XmlDocument();
           xmlDoc.Load("data.xml");

•            XmlNodeList nodeList = xmlDoc.SelectSingleNode("Employees").ChildNodes;//获取Employees节点的所有子节点   
•            foreach (XmlNode xn in nodeList)//遍历所有子节点   
•            {  
•                XmlElement xe = (XmlElement)xn;//将子节点类型转换为XmlElement类型   
•                if (xe.GetAttribute("genre") == "张三")//如果genre属性值为“张三”   
•                {  
•                    xe.SetAttribute("genre", "update张三");//则修改该属性为“update张三”   
•                    XmlNodeList nls = xe.ChildNodes;//继续获取xe子节点的所有子节点   
•                    foreach (XmlNode xn1 in nls)//遍历   
•                    {  
•                        XmlElement xe2 = (XmlElement)xn1;//转换类型   
•                        if (xe2.Name == "author")//如果找到   
•                        {  
•                            xe2.InnerText = "亚胜";//则修改   
•                        }  
•                    }  
•                }  
•            }  
•            xmlDoc.Save("data.xml");//保存。  

XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load("data.xml"); XmlNodeList nodeList = xmlDoc.SelectSingleNode("Employees").ChildNodes;//获取Employees节点的所有子节点 foreach (XmlNode xn in nodeList)//遍历所有子节点 { XmlElement xe = (XmlElement)xn;//将子节点类型转换为XmlElement类型 if (xe.GetAttribute("genre") == "张三")//如果genre属性值为“张三” { xe.SetAttribute("genre", "update张三");//则修改该属性为“update张三” XmlNodeList nls = xe.ChildNodes;//继续获取xe子节点的所有子节点 foreach (XmlNode xn1 in nls)//遍历 { XmlElement xe2 = (XmlElement)xn1;//转换类型 if (xe2.Name == "author")//如果找到 { xe2.InnerText = "亚胜";//则修改 } } } } xmlDoc.Save("data.xml");//保存。  

4、修改结点（添加结点的属性和添加结点的自结点）

XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load("data.xml");

•             XmlNodeList nodeList = xmlDoc.SelectSingleNode("Employees").ChildNodes;//获取Employees节点的所有子节点   
•             foreach (XmlNode xn in nodeList)  
•             {  
•                 XmlElement xe = (XmlElement)xn;  
•                 xe.SetAttribute("test", "111111");  
•                 XmlElement xesub = xmlDoc.CreateElement("flag");  
•                 xesub.InnerText = "1";  
•                 xe.AppendChild(xesub);  
•             }  
•             xmlDoc.Save("data.xml");  

XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load("data.xml"); XmlNodeList nodeList = xmlDoc.SelectSingleNode("Employees").ChildNodes;//获取Employees节点的所有子节点 foreach (XmlNode xn in nodeList) { XmlElement xe = (XmlElement)xn; xe.SetAttribute("test", "111111"); XmlElement xesub = xmlDoc.CreateElement("flag"); xesub.InnerText = "1"; xe.AppendChild(xesub); } xmlDoc.Save("data.xml");  

5、删除结点中的某一个属性

XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load("data.xml");

•             XmlNodeList xnl = xmlDoc.SelectSingleNode("Employees").ChildNodes;  
•             foreach (XmlNode xn in xnl)  
•             {  
•                 XmlElement xe = (XmlElement)xn;  
•                 xe.RemoveAttribute("genre");//删除genre属性   
•                 XmlNodeList nls = xe.ChildNodes;//继续获取xe子节点的所有子节点   
•                 foreach (XmlNode xn1 in nls)//遍历   
•                 {  
•                     XmlElement xe2 = (XmlElement)xn1;//转换类型   
•                     if (xe2.Name == "flag")//如果找到   
•                     {  
•                         xe.RemoveChild(xe2);//则删除   
•                     }  
•                 }  
•             }  
•             xmlDoc.Save("data.xml");   

XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load("data.xml"); XmlNodeList xnl = xmlDoc.SelectSingleNode("Employees").ChildNodes; foreach (XmlNode xn in xnl) { XmlElement xe = (XmlElement)xn; xe.RemoveAttribute("genre");//删除genre属性 XmlNodeList nls = xe.ChildNodes;//继续获取xe子节点的所有子节点 foreach (XmlNode xn1 in nls)//遍历 { XmlElement xe2 = (XmlElement)xn1;//转换类型 if (xe2.Name == "flag")//如果找到 { xe.RemoveChild(xe2);//则删除 } } } xmlDoc.Save("data.xml");

6、删除结点

XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load("data.xml");

•             XmlNode root = xmlDoc.SelectSingleNode("Employees");  
•             XmlNodeList xnl = xmlDoc.SelectSingleNode("Employees").ChildNodes;  
•             for (int i = 0; i < xnl.Count; i++)  
•             {  
•                 XmlElement xe = (XmlElement)xnl.Item(i);  
•                 if (xe.GetAttribute("genre") == "张三")  
•                 {  
•                     root.RemoveChild(xe);  
•                     if (i < xnl.Count) i = i - 1;  
•                 }  
•             }  
•             xmlDoc.Save("data.xml");   

XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load("data.xml"); XmlNode root = xmlDoc.SelectSingleNode("Employees"); XmlNodeList xnl = xmlDoc.SelectSingleNode("Employees").ChildNodes; for (int i = 0; i < xnl.Count; i++) { XmlElement xe = (XmlElement)xnl.Item(i); if (xe.GetAttribute("genre") == "张三") { root.RemoveChild(xe); if (i < xnl.Count) i = i - 1; } } xmlDoc.Save("data.xml");

7、按照文本文件读取xml

System.IO.StreamReader myFile = new System.IO.StreamReader("data.xml", System.Text.Encoding.Default);
            //注意System.Text.Encoding.Default

•             string myString = myFile.ReadToEnd();//myString是读出的字符串   
•             this.textBox1.Text = myString;  
•             myFile.Close();  

System.IO.StreamReader myFile = new System.IO.StreamReader("data.xml", System.Text.Encoding.Default); //注意System.Text.Encoding.Default string myString = myFile.ReadToEnd();//myString是读出的字符串 this.textBox1.Text = myString; myFile.Close();  

8、读取xml

//创建XmlDocument对象
XmlDocument xmlDoc = new XmlDocument();

• //载入xml文件名   
• xmlDoc.Load(filename);   
• //如果是xml字符串，则用以下形式   
• xmlDoc.LoadXml(xmldata);   
• //读取根节点的所有子节点，放到xn0中    
• XmlNodeList xn0 = xmlDoc.SelectSingleNode("Document").ChildNodes;   
• //查找二级节点的内容或属性    
• foreach (XmlNode node in xn0)  
• {  
•     if (node.Name == 匹配的二级节点名)  
•     {  
•         string innertext = node.InnerText.Trim();//匹配二级节点的内容   
•         string attr = node.Attributes[0].ToString();//属性   
•     }   
• }   
• 基础的操作就是这些，要是取三级或三级以上的节点，类似推导即可  

-----------------------------------------------------------------------

一个XML的操作类：

包括读取/插入/修改/删除。

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Xml;

namespace Test
{
    /// <summary>
    /// XmlHelper 的摘要说明
    /// </summary>
    public class XmlHelper
    {
        public XmlHelper()
        {
        }

        /// <summary>
        /// 读取数据
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="attribute">属性名，非空时返回该属性值，否则返回串联值</param>
        /// <returns>string</returns>
        /**************************************************
         * 使用示列:
         * XmlHelper.Read(path, "/Node", "")
         * XmlHelper.Read(path, "/Node/Element[@Attribute='Name']", "Attribute")
         ************************************************/
        public static string Read(string path, string node, string attribute)
        {
            string value = "";
            try
            {
                XmlDocument doc = new XmlDocument();
                doc.Load(path);
                XmlNode xn = doc.SelectSingleNode(node);
                value = (attribute.Equals("") ? xn.InnerText : xn.Attributes[attribute].Value);
            }
            catch { }
            return value;
        }

        /// <summary>
        /// 插入数据
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="element">元素名，非空时插入新元素，否则在该元素中插入属性</param>
        /// <param name="attribute">属性名，非空时插入该元素属性值，否则插入元素值</param>
        /// <param name="value">值</param>
        /// <returns></returns>
        /**************************************************
         * 使用示列:
         * XmlHelper.Insert(path, "/Node", "Element", "", "Value")
         * XmlHelper.Insert(path, "/Node", "Element", "Attribute", "Value")
         * XmlHelper.Insert(path, "/Node", "", "Attribute", "Value")
         ************************************************/
        public static void Insert(string path, string node, string element, string attribute, string value)
        {
            try
            {
                XmlDocument doc = new XmlDocument();
                doc.Load(path);
                XmlNode xn = doc.SelectSingleNode(node);
                if (element.Equals(""))
                {
                    if (!attribute.Equals(""))
                    {
                        XmlElement xe = (XmlElement)xn;
                        xe.SetAttribute(attribute, value);
                    }
                }
                else
                {
                    XmlElement xe = doc.CreateElement(element);
                    if (attribute.Equals(""))
                        xe.InnerText = value;
                    else
                        xe.SetAttribute(attribute, value);
                    xn.AppendChild(xe);
                }
                doc.Save(path);
            }
            catch { }
        }

        /// <summary>
        /// 修改数据
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="attribute">属性名，非空时修改该节点属性值，否则修改节点值</param>
        /// <param name="value">值</param>
        /// <returns></returns>
        /**************************************************
         * 使用示列:
         * XmlHelper.Insert(path, "/Node", "", "Value")
         * XmlHelper.Insert(path, "/Node", "Attribute", "Value")
         ************************************************/
        public static void Update(string path, string node, string attribute, string value)
        {
            try
            {
                XmlDocument doc = new XmlDocument();
                doc.Load(path);
                XmlNode xn = doc.SelectSingleNode(node);
                XmlElement xe = (XmlElement)xn;
                if (attribute.Equals(""))
                    xe.InnerText = value;
                else
                    xe.SetAttribute(attribute, value);
                doc.Save(path);
            }
            catch { }
        }

        /// <summary>
        /// 删除数据
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="node">节点</param>
        /// <param name="attribute">属性名，非空时删除该节点属性值，否则删除节点值</param>
        /// <param name="value">值</param>
        /// <returns></returns>
        /**************************************************
         * 使用示列:
         * XmlHelper.Delete(path, "/Node", "")
         * XmlHelper.Delete(path, "/Node", "Attribute")
         ************************************************/
        public static void Delete(string path, string node, string attribute)
        {
            try
            {
                XmlDocument doc = new XmlDocument();
                doc.Load(path);
                XmlNode xn = doc.SelectSingleNode(node);
                XmlElement xe = (XmlElement)xn;
                if (attribute.Equals(""))
                    xn.ParentNode.RemoveChild(xn);
                else
                    xe.RemoveAttribute(attribute);
                doc.Save(path);
            }
            catch { }
        }
    }
}

==================================================

XmlFile.xml：
<?xml version="1.0" encoding="utf-8"?>
<Root />

==================================================

使用方法：

string xml = Server.MapPath("XmlFile.xml");
//插入元素
//XmlHelper.Insert(xml, "/Root", "Studio", "", "");
//插入元素/属性
//XmlHelper.Insert(xml, "/Root/Studio", "Site", "Name", "小路工作室");
//XmlHelper.Insert(xml, "/Root/Studio", "Site", "Name", "丁香鱼工作室");
//XmlHelper.Insert(xml, "/Root/Studio", "Site", "Name", "谱天城工作室");
//XmlHelper.Insert(xml, "/Root/Studio/Site[@Name='谱天城工作室']", "Master", "", "红尘静思");
//插入属性
//XmlHelper.Insert(xml, "/Root/Studio/Site[@Name='小路工作室']", "", "Url", "http://www.wzlu.com/");
//XmlHelper.Insert(xml, "/Root/Studio/Site[@Name='丁香鱼工作室']", "", "Url", "http://www.luckfish.net/");
//XmlHelper.Insert(xml, "/Root/Studio/Site[@Name='谱天城工作室']", "", "Url", "http://www.putiancheng.com/");
//修改元素值
//XmlHelper.Update(xml, "/Root/Studio/Site[@Name='谱天城工作室']/Master", "", "RedDust");
//修改属性值
//XmlHelper.Update(xml, "/Root/Studio/Site[@Name='谱天城工作室']", "Url", "http://www.putiancheng.net/");
//XmlHelper.Update(xml, "/Root/Studio/Site[@Name='谱天城工作室']", "Name", "PuTianCheng Studio");
//读取元素值
//Response.Write("<div>" + XmlHelper.Read(xml, "/Root/Studio/Site/Master", "") + "</div>");
//读取属性值
//Response.Write("<div>" + XmlHelper.Read(xml, "/Root/Studio/Site", "Url") + "</div>");
//读取特定属性值
//Response.Write("<div>" + XmlHelper.Read(xml, "/Root/Studio/Site[@Name='丁香鱼工作室']", "Url") + "</div>");
//删除属性
//XmlHelper.Delete(xml, "/Root/Studio/Site[@Name='小路工作室']", "Url");
//删除元素
//XmlHelper.Delete(xml, "/Root/Studio", "");