C# 读写xml文件总结
- C#写入xml文件
- 1、XmlDocument
- 2、DataSet对象里的值来生成XML文件
- 3、利用XmlSerializer来将类的属性值转换为XML文件的元素值。
- 示例：写入xml
- 1、创建xml文档
- 2 、增加节点
- 3 、修改节点：
- 4 、删除节点
- c#读取xml文件
C#写入xml文件
1、XmlDocument
1。我认为是最原始，最基本的一种：利用XmlDocument向一个XML文件里写节点，然后再利用XmlDocument保存文件。
首先加载要写入的XML文件，但是如果没有的，就要新建，在新建的过程中，要有写入的代码；
XmlDocument doc = new XmlDocument();try{doc.Load("new.xml");}catch{XmlTextWriter xtw = new XmlTextWriter("new.xml", Encoding.UTF8);//新建XML文件xtw.WriteStartDocument();xtw.WriteStartElement("gnode");// gnode根节点 xtw.WriteStartElement("myxm1");// gnode根节点下的元素myxmls xtw.WriteEndElement();xtw.WriteEndElement();xtw.WriteEndDocument();xtw.Close();doc.Load("new.xml");}XmlNode xn = doc.DocumentElement;//找到根节点 XmlElement xe = doc.CreateElement("myxml2");//在根节点下创建元素，如果是属性，则用XmlAttribute； xe.InnerText = "薪薪代码hahaha";//给子节点写入文本节点（值） xn.AppendChild(xe);//根节点将其纳入 doc.Save("new2.xml");//利用XmlDocument保存文件}注意点：在新建根节点的时候，WriteStartElement，只能嵌套，也就是只能有一个根节点。
2、DataSet对象里的值来生成XML文件
应用到数据库，将数据库的DataSet对象里的值来生成XML文件的元素；
using (SqlConnection con = new SqlConnection("Server=.;DataBase=HGSTUDY;uid=sa;pwd=yao")){con.Open();SqlCommand command = new SqlCommand("select * from GL_STUDY", con);command.CommandType = CommandType.Text;DataSet ds = new DataSet("DATASET");//DATASET将成为XML文件中的根节点名称，否则系统将其命名为NewDataSetSqlDataAdapter sda = new SqlDataAdapter();sda.SelectCommand = command;sda.Fill(ds, "DATATABLE");//DATATABLE为所生成XML文件中的子节点名称，否则系统将其命名为Table。 ds.WriteXml("dbxml.xml");// DataSet的方法WriteXml将数据写入到XML文件，就是这么一句话。如果不保存到文件，直接ds.GetXML()}3、利用XmlSerializer来将类的属性值转换为XML文件的元素值。
用一个字符串作为一个XML文档中的xmlAttribute或xmlElement。[其元素或属性由类的定义来设置(xml串行化)]
using System;System.xml.Serialization;
- 先初始化一个类，设置属性值
var xmlDoc = new XmlDocument();//Create the xml declaration firstxmlDoc.AppendChild(xmlDoc.CreateXmlDeclaration("1.0", "utf-8", null));//Create the root node and append into docvar el = xmlDoc.CreateElement("Contacts");xmlDoc.AppendChild(el);// ContactXmlElement elementContact = xmlDoc.CreateElement("Contact");XmlAttribute attrID = xmlDoc.CreateAttribute("id");attrID.Value = "01";elementContact.Attributes.Append(attrID);el.AppendChild(elementContact);// Contact NameXmlElement elementName = xmlDoc.CreateElement("Name");elementName.InnerText = "Daisy Abbey";elementContact.AppendChild(elementName);// Contact GenderXmlElement elementGender = xmlDoc.CreateElement("Gender");elementGender.InnerText = "female";elementContact.AppendChild(elementGender);xmlDoc.Save("test1.xml");- 建XmlSerializer实例
class XXX { XmlSerializer ser = new XmlSerializer(Type.GetType("forxml.truck"));Truck tr = new Truck();tr.ID = 1; tr.cheID = "赣A T34923"; }- Serialize方法–完成对类的串行化
XmlTextWriter xtw = new XmlTextWriter("myxml.xml",Encoding.UTF8); 用XmlTextWriter 创建一个XML文件ser.Serialize(xtw, tr); //如果只想显示，可以直接ser.Serialize(Console.Out, tr);}xml常用方法：
定义xml文档：XmlDocument xmlDoc = new XmlDocument();
初始化xml文档：xmlDoc.Load(“D:\book.xml”);//找到xml文件
创建根元素：XmlElement xmlElement = xmlDoc.CreateElement(“”, “Employees”, “”);
创建节点：XmlElement xeSub1 = xmlDoc.CreateElement(“title”);
查找Employees节点：XmlNode root = xmlDoc.SelectSingleNode(“Employees”);
添加节点：xe1.AppendChild(xeSub1);
更改节点的属性：xe.SetAttribute(“Name”, “李明明”);
移除xe的ID属性：xe.RemoveAttribute(“ID”);
删除节点title：xe.RemoveChild(xe2);
示例：写入xml
1、创建xml文档
public void CreateXMLDocument(){XmlDocument xmlDoc = new XmlDocument();//加入XML的声明段落,XmlDeclaration xmlDeclar;xmlDeclar = xmlDoc.CreateXmlDeclaration("1.0", "gb2312", null);xmlDoc.AppendChild(xmlDeclar);//加入Employees根元素XmlElement xmlElement = xmlDoc.CreateElement("", "Employees", "");xmlDoc.AppendChild(xmlElement);//添加节点XmlNode root = xmlDoc.SelectSingleNode("Employees");XmlElement xe1 = xmlDoc.CreateElement("Node");xe1.SetAttribute("Name", "薪薪代码");xe1.SetAttribute("ISB", "2-3631-4");//添加子节点XmlElement xeSub1 = xmlDoc.CreateElement("title");xeSub1.InnerText = "学习VS";xe1.AppendChild(xeSub1);XmlElement xeSub2 = xmlDoc.CreateElement("price");xe1.AppendChild(xeSub2);XmlElement xeSub3 = xmlDoc.CreateElement("weight");xeSub3.InnerText = "20";xeSub2.AppendChild(xeSub3);root.AppendChild(xe1);xmlDoc.Save("D:\\book.xml");//保存的路径}生成的xml文件如下：
<?xml version="1.0" encoding="GB2312"?>-<Employees>- <Node ISB="2-3631-4" Name="薪薪代码"> <title>学习VS</title>- <price> <weight>20</weight> </price> </Node></Employees>2 、增加节点
XmlDocument xmlDoc = new XmlDocument();xmlDoc.Load("D:\\book.xml");//找到xml文件XmlNode root = xmlDoc.SelectSingleNode("Employees");//查找Employees节点XmlElement xe1 = xmlDoc.CreateElement("Node2");//添加Node2节点xe1.SetAttribute("Name", "张飞");XmlElement xeSub1 = xmlDoc.CreateElement("title");//定义子节点xeSub1.InnerText = "心情好";xe1.AppendChild(xeSub1);//添加节点到Node2root.AppendChild(xe1);//添加节点到EmployeesxmlDoc.Save("D:\\book.xml");结果：
<?xml version="1.0" encoding="GB2312"?> -<Employees> -<Node ISB="2-3631-4" Name="薪薪代码"> <title>学习VS</title>- <price> <weight>20</weight> </price> </Node>- <Node2 Name="张三"> <title>心情好</title> </Node2>- <Node2 Name="张三"> <title>心情好</title> </Node2></Employees>3 、修改节点：
public void ModifyNode(){XmlDocument xmlDocument = new XmlDocument();xmlDocument.Load("D:\\book.xml");XmlNodeList nodeList = xmlDocument.SelectSingleNode("Employees").ChildNodes;//获取Employees节点的所有子节点foreach (XmlNode xn in nodeList)//遍历{ XmlElement xe = (XmlElement)xn; if (xe.GetAttribute("Name") == "薪薪代码") { xe.SetAttribute("Name", "薪薪");//更改节点的属性 XmlNodeList xnl = xe.ChildNodes;//获取xe的所有子节点 foreach (XmlNode xn1 in xnl) {XmlElement xe2 = (XmlElement)xn1;//将节点xn1的属性转换为XmlElementif (xe2.Name == "title")//找到节点名字为title的节点{xe2.InnerText = "今天天气不好";}if (xe2.Name == "price"){XmlNodeList xnl2 = xe2.ChildNodes;foreach (XmlNode xn2 in xnl2){ if (xn2.Name == "weight") { xn2.InnerText = "88"; }}} } }}xmlDocument.Save("D:\\book2.xml");}运行结果:
<?xml version="1.0" encoding="GB2312"?>-<Employees>-<Node ISB="2-3631-4" Name="薪薪"><title>今天天气不好</title>-<price><weight>88</weight></price></Node>-<Node2 Name="张三"><title>心情好</title></Node2></Employees>4 、删除节点
public void DeleteNode(){XmlDocument xmlDocument = new XmlDocument();xmlDocument.Load("D:\\book1.xml");XmlNodeList xnl = xmlDocument.SelectSingleNode("Employees").ChildNodes;foreach (XmlNode xn in xnl){ if (xn.Name == "Node") { XmlElement xe = (XmlElement)xn;//将xn的属性转换为XmlElement xe.RemoveAttribute("ID");//移除xe的ID属性 XmlNodeList xnl2 = xe.ChildNodes; for (int i = 0; i < xnl2.Count; i++) {XmlElement xe2 = (XmlElement)xnl2.Item(i);if (xe2.Name == "title"){xe.RemoveChild(xe2);//删除节点title} } }}xmlDocument.Save("D:\\book3.xml");}结果：
<?xml version="1.0" encoding="GB2312"?>-<Employees>-<Node ISB="2-3631-4" Name="薪薪">-<price><weight>20</weight></price></Node>-<Node2 Name="张三"><title>心情好</title></Node2>-<Node2 Name="张三"><title>心情好</title></Node2></Employees>c#读取xml文件
xml文件如下：
<?xml version="1.0" encoding="utf-8" ?><configurationN><ServerAddress>1143</ServerAddress><ID>192.168</ID></configurationN>在写入xml文件时，最主要使用了两个方法：Load和Save。
Load：初始化xml文档，以便项目文件获取具体的xml节点的值。
public void Load(string path){try{ XmlDocument xmlDocument = new XmlDocument(); xmlDocument.Load(path); XmlNodeList xnl = xmlDocument.SelectSingleNode(managerNode).ChildNodes; foreach (XmlNode xn in xnl) { if (xn.Name == configuration_ServerAddress) {ServerAddress = xn.InnerText; } }}catch(Exception ex){ }}Save：在项目系统中进行修改配置文件值后，需要对xml进行重新保存
public void Save(string path){try{ XmlDocument xmlDocument = new XmlDocument(); xmlDocument.Load(path); XmlNodeList xnl = xmlDocument.SelectSingleNode(managerNode).ChildNodes; foreach (XmlNode xn in xnl) { if (xn.Name == configuration_ServerAddress) {xn.InnerText = ServerAddress; } } xmlDocument.Save(path);}catch (Exception ex){ }}此处将所有代码都贴出来，方便下次实现。因为项目是WPF文件，而且都是简单控件，所以只贴出后台代码。
class ConfigurationManager:INotifyPropertyChanged{public const string managerNode = "configurationN";//根节点public const string configuration_ServerAddress = "ServerAddress";//子节点private string _ServerAddress;public string ServerAddress{get { return _ServerAddress; }set{_ServerAddress = value;NotifyPropertyChanged("ServerAddress");}}public void Load(string path){try{XmlDocument xmlDocument = new XmlDocument();xmlDocument.Load(path);XmlNodeList xnl = xmlDocument.SelectSingleNode(managerNode).ChildNodes;foreach (XmlNode xn in xnl){if (xn.Name == configuration_ServerAddress){ServerAddress = xn.InnerText;}}}catch(Exception ex){ }}public void Save(string path){try{XmlDocument xmlDocument = new XmlDocument();xmlDocument.Load(path);XmlNodeList xnl = xmlDocument.SelectSingleNode(managerNode).ChildNodes;foreach (XmlNode xn in xnl){if (xn.Name == configuration_ServerAddress){xn.InnerText = ServerAddress;}}xmlDocument.Save(path);}catch (Exception ex){ }}public event PropertyChangedEventHandler PropertyChanged;private void NotifyPropertyChanged(string propertyName){if (PropertyChanged != null){PropertyChanged(this, new PropertyChangedEventArgs(propertyName));}}public static ConfigurationManager Instance = new ConfigurationManager();}public partial class MainWindow : Window{public MainWindow(){InitializeComponent();Start();this.tb1.Text = ConfigurationManager.Instance.ServerAddress.ToString();}private string path = "CONFIG\\System.xml";private void button1_Click(object sender, RoutedEventArgs e){ConfigurationManager.Instance.ServerAddress = this.tb1.Text;ConfigurationManager.Instance.Save(path);}private void button2_Click(object sender, RoutedEventArgs e){Application.Current.Shutdown();}private void Start(){ConfigurationManager.Instance.Load(path);}}