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NewDataSet      
                SqlDataAdapter 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;

  1. 先初始化一个类,设置属性值
var xmlDoc = new XmlDocument();
//Create the xml declaration first
xmlDoc.AppendChild(xmlDoc.CreateXmlDeclaration("1.0", "utf-8", null));
//Create the root node and append into doc
var el = xmlDoc.CreateElement("Contacts");
xmlDoc.AppendChild(el);
// Contact
XmlElement elementContact = xmlDoc.CreateElement("Contact");
XmlAttribute attrID = xmlDoc.CreateAttribute("id");
attrID.Value = "01";
elementContact.Attributes.Append(attrID);
el.AppendChild(elementContact);
// Contact Name
XmlElement elementName = xmlDoc.CreateElement("Name");
elementName.InnerText = "Daisy Abbey";
elementContact.AppendChild(elementName);
// Contact Gender
XmlElement elementGender = xmlDoc.CreateElement("Gender");
elementGender.InnerText = "female";
elementContact.AppendChild(elementGender);
xmlDoc.Save("test1.xml");
  1. 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";
           }
  1. 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,<?xml version="1.0" encoding="gb2312"?>
    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Node2
root.AppendChild(xe1);//添加节点到Employees
xmlDoc.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XmlElement
  if (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);
        }
}
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