Xml增删改查 和ling to Xml

<?xml version="1.0" encoding="utf-8"?>
<books>
  <book1>
    <name>水浒传</name>
    <author>作者</author>
  </book1>
  <Student studentId="10">
    <Name>我是学生1</Name>
    <Sex>
      <a>男</a>
    </Sex>
    <price name="价格" count="1000"    />
  </Student>
</books>

1增

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;

namespace ConsoleApplication10
{
    class Program
    {
        static void Main(string[] args)
        {
            XmlDocument doc = new XmlDocument();
            //先判断xml文件是否已经存在，如果存在，就追加；不存在，新建。
            if(File.Exists("a.xml"))
            {
                //存在
                //先加载进来
                doc.Load("a.xml");
                //获得根节点
                 XmlElement gen=  doc.DocumentElement;

                //给根节点添加子节点
                 XmlElement student1 = doc.CreateElement("Student");
                //设置标签属性
                 student1.SetAttribute("studentId","10");
                 gen.AppendChild(student1);
                //添加子子标签
                 XmlElement name1 = doc.CreateElement("Name");
                 name1.InnerXml = "我是学生1";
                 student1.AppendChild(name1);
                // XmlElement sex1 = doc.CreateElement("Sex"); sex1.InnerXml = "<a>男</a>";
                 XmlElement sex1 = doc.CreateElement("Sex"); sex1.InnerXml = "男";
                 student1.AppendChild(sex1);
            }
            else
            {
            //不存在
                XmlDeclaration dec = doc.CreateXmlDeclaration("1.0","utf-8",null);
                doc.AppendChild(dec);
                XmlElement gen = doc.CreateElement("gen");
                doc.AppendChild(gen);

                //给根节点添加子节点
                XmlElement student1 = doc.CreateElement("Student");
                //设置标签属性
                student1.SetAttribute("studentId", "10");
                gen.AppendChild(student1);
                //添加子子标签
                XmlElement name1 = doc.CreateElement("Name");
                name1.InnerXml = "我是学生1";
                student1.AppendChild(name1);
                // XmlElement sex1 = doc.CreateElement("Sex"); sex1.InnerXml = "<a>男</a>";
                XmlElement sex1 = doc.CreateElement("Sex"); sex1.InnerXml = "男";
                student1.AppendChild(sex1);
            }
            //最终都要保存
            doc.Save("a.xml");
            Console.WriteLine("保存成功");
        }
    }
}

2删

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;

namespace ConsoleApplication10
{
    class Program
    {
        static void Main(string[] args)
        {
        
            XmlDocument doc = new XmlDocument();
            doc.Load("a.xml");
           // doc.RemoveAll();//不行，根节点不允许删除
            XmlNode gen = doc.DocumentElement;
            //gen.RemoveAll();//移除根节点下所有的子节点
            #region 删除一个指定的标签
            ////寻找指定的节点,注意path格式
            //XmlNode xn = gen.SelectSingleNode("/books/Student/price[@name='价格']");
            ////获得上面price节点的上节点
            //XmlNode shangxn = doc.SelectSingleNode("/books/Student");
            //shangxn.RemoveChild(xn);//删除方法必须是上一个节点删除下一个节点
            #endregion


            #region 删除一个指定的标签内的属性
            //寻找指定标签
            XmlNode xn = gen.SelectSingleNode("/books/Student/price[@name='价格']");
            //删除指定标签内的属性
            xn.Attributes.RemoveNamedItem("count");
            #endregion


            doc.Save("a.xml");
            Console.WriteLine("删除成功");
            Console.ReadLine();



        }
    }
}

3查改

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;

namespace ConsoleApplication10
{
    class Program
    {
        static void Main(string[] args)
        {
            #region 普通方法查询
           // XmlDocument doc = new XmlDocument();
           ////获得根节点
           // XmlElement gen = doc.DocumentElement;
           // //获得根节点下所有的子节点 
           // XmlNodeList xnl = gen.ChildNodes;
           // foreach (XmlNode xn in xnl)
           // {
           //     Console.WriteLine(xn.InnerText);//获取所有子节点的值
           //     //但是如果有属性，就获取不到属性的值
           // }


           // //<Sex><a>男</a></Sex>,只有一个这样的标签
           // XmlElement items = gen["Sex"];//根据标签查找
           
           // XmlNodeList xnl2 = items.ChildNodes;
           // foreach (XmlNode xn in xnl2)
           // {
           //     Console.WriteLine(xn.Attributes["a"].Value);//得到“男”
           // }
           // //最终都要保存
           // doc.Save("a.xml");
           // Console.WriteLine("保存成功");
            #endregion

            #region 使用XPath的方式来读取XML文件
            XmlDocument doc = new XmlDocument();
            doc.Load("a.xml");
            //获得根节点
            XmlElement gen = doc.DocumentElement;

            //XmlNode xn = gen.SelectSingleNode("/books/book1/name");//  "/根节点/子节点/包裹值得标签"
            //Console.WriteLine(xn.InnerText);

            XmlNode xn = gen.SelectSingleNode("/books/Student/price[@name='价格']");//  "/根节点/子节点/子节点内的标签[@标签属性='属性值']"
            Console.WriteLine(xn.Attributes["count"].Value);//取值 count为标签内属性
            xn.Attributes["count"].Value = "2000";//修改值


            doc.Save("a.xml");//保存
            Console.ReadKey();

            #endregion



        }
    }
}

linq to Xml

using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Linq;
using System.Windows.Forms;
using System.Xml.Linq;

namespace xml
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        static string ddd = "ddd.xml";//全局变量，将要操作对的文件
        private void Form1_Load(object sender, EventArgs e)
        {
            textBox1.Text = LoadForm().ToString();

        }
        /// <summary>
        /// 加载原始数据
        /// </summary>
        /// <returns></returns>
        public static XDocument LoadForm()
        {
            
            XDocument newXelem = null;
            if (File.Exists(ddd))
                newXelem = XDocument.Load(ddd);
            else
            {
                List<people> pList = new List<people>();
                for (int i = 0; i < 10; i++)
                    pList.Add(new people { name="name"+i, age=100+i});
                newXelem = new XDocument("people",
                   from p in pList select new XElement("person",
                                              new XAttribute("age",p.age),
                                              new XElement("name",p.name))
                    );
            }
            newXelem.Save(ddd);
            return newXelem;
        }


        /// <summary>
        /// parse和load方法加载xml文件
        /// </summary>
        public static void ParseAndLoadExistXml()
        {
            string xml = File.ReadAllText("ccc.xml");
            //parse方法
            XElement newElem = XElement.Parse(xml);
            Console.WriteLine(newElem);

            Console.WriteLine("-----------");
            //load方法
            XElement newElem2 = XElement.Load("aaa.xml");
            Console.WriteLine(newElem2);
        }

        /// <summary>
        /// 从数据源（数组或集合）中获取数据创建xml文件
        /// </summary>
        public static void MakeXelementFormArray()
        {
            List<people> pList = new List<people>();
            for (int i = 0; i < 10; i++)
            {
                pList.Add(new people { name = "name" + i, age = 100 + i });
            }
            XElement peopleDoc = new XElement("pepole",
                //linq加载数据源数据
                from p in pList
                select new XElement("person",
                            new XAttribute("age", p.age),
                            new XElement("name", p.name))
                );
            peopleDoc.Save("ccc.xml");
        }
        /// <summary>
        /// 创建简单xml文件2
        /// </summary>
        public static void CreateFullXdocment()
        {
            XDocument invenDoc = new XDocument(
                new XDeclaration("1.0", "utf-8", "yes"),
                new XComment("current inventory of Cars"),
                new XProcessingInstruction("xml-stylesheet", "href='MyStyle'"),
                new XElement("inventory",
                     new XElement("Car", new XAttribute("ID", "1"),
                       new XElement("color", "Green"),
                       new XElement("make", "BMW"),
                       new XElement("petname", "stan")),
                     new XElement("Car", new XAttribute("ID", "2"),
                       new XElement("color", "Pink"),
                       new XElement("make", "YuGo"),
                       new XElement("petname", "Melvin"))
                     )
                );

            invenDoc.Save("bbb.xml");
        }

        /// <summary>
        /// 创建简单xml文件1
        /// </summary>
        public static void BuildDocWithLinqToXml()
        {
            XElement doc =
               new XElement("Inventory",
                   new XElement("Car", new XAttribute("ID", "1000"),
                      new XElement("PetName", "Jimbo"),
                      new XElement("Color", "Red"),
                      new XElement("Make", "Ford")
                   ));
            doc.Descendants("PetName").Remove();
            doc.Save("aaa.xml");
        }

        private void btAdd_Click(object sender, EventArgs e)
        {
            try
            {
                string name = tbName.Text.Trim();
                int age = int.Parse(tbAge.Text.Trim());
                InsertPeople(name,age);

            }
            catch (Exception exp)
            {
                MessageBox.Show(exp.ToString());
            }
        }
        public static void InsertPeople(string name,int age)
        {
            XDocument doc = XDocument.Load(ddd);
            Random r = new Random();
            XElement xele = new XElement("person",
                new XAttribute("ID",r.Next(5000)),
                new XAttribute("age",age),
                new XElement("name",name+age));
            doc.Descendants("people").Last().Add(xele);
            doc.Save(ddd);
        }

        private void btAurey_Click(object sender, EventArgs e)
        {
            SearchByAge(int.Parse(tbQuery.Text.Trim()));
        }
        /// <summary>
        /// 根据属性（年龄）来查找符合条件的人的姓名
        /// </summary>
        /// <param name="age"></param>
        public static void SearchByAge(int age)
        {
            XDocument doc = XDocument.Load(ddd);
            //查找
            var ageInfo = from person in doc.Descendants("person")
                          where (int)person.Attribute("age") < age
                          select person.Element("name").Value;
            string data = string.Empty;
            foreach (var item in ageInfo.Distinct())
            {
                data += item + "===";
            }
            MessageBox.Show(data);

        }
    }
    class people
    {
        public string name { get; set; }
        public int age { get; set; }
    }
}

完！！