C#读写xml

先用vs2017建立一个xml文件

<?xml version="1.0" encoding="ISO-8859-1"?>
<bookstore>
<!--记录书本的信息-->
<book ISBN="7-111-19149-2" Type="必修课">
<title>数据结构</title>
<author>严蔚敏</author>
<price>30.00</price>
</book>
<book ISBN="7-111-19149-3" Type="必修课">
<title>路由型与交换型互联网基础</title>
<author>程庆梅</author>
<price>27.00</price>
</book>
<book ISBN="7-111-19149-4" Type="必修课">
<title>计算机硬件技术基础</title>
<author>李继灿</author>
<price>25.00</price>
</book>
<book ISBN="12345678" Type="必修课">
<title>软件质量保证与管理</title>
<author>朱少民</author>
<price>39.00</price>
</book>
</bookstore>

创建C#控制台 ，使用预处理头文件

using System;

using System.Collections.Generic;

using System.Xml;

创建book类：

public class BookModel
        {
            public BookModel() { }
            //所对应的课程类型
            private string bookType;
            private string bookISBN;
            private string bookName;
            private string bookAuthor;
            private double bookPrice;
            public string BookType
            {
                get { return bookType; }
                set { bookType = value; }
            }
            public string BookISBN
            {
                get { return bookISBN; }
                set { bookISBN = value; }
            }
            public string BookName
            {
                get { return bookName; }
                set { bookName = value; }
            }
            public string BookAuthor
            {
                get { return bookAuthor; }
                set { bookAuthor = value; }
            }
            public double BookPrice
            {
                get { return bookPrice; }
                set { bookPrice = value; }
            }
        }

读取xml，并将他添加到 books 集合中：

static private void copy(List<BookModel> books)
        {//将xml加载进来
            XmlDocument doc = new XmlDocument();

            doc.Load(@"C:UsersLinDesktop机试2xmlookstore.xml");
            //获取 book 节点集合
            XmlNodeList bookNodes = doc.SelectNodes("bookstore/book");
            foreach (XmlNode node in bookNodes)
            {
                BookModel book = new BookModel();
                //获取book的属性值
　　　　　　　　　book.BookISBN=node.Attributes["ISBN"].InnerText;
　　　　　　　　　　book.BookType=node.Attributes["Type"].InnerText;
　　　　　　　　　//获取 book 子节点的内容
                book.BookName = node.ChildNodes[0].InnerText;
                book.BookAuthor = node.ChildNodes[1].InnerText;
                book.BookPrice = Convert.ToDouble(node.ChildNodes[2].InnerText);

                //插入到 books 集合中
                books.Add(book);
            }
            foreach(BookModel book in books)
            {
                Console.WriteLine("{0},{1},{2}", book.BookName, book.BookAuthor, book.BookPrice);
            }
        }

向xml中添加新的 book 节点：

        private static void addNewNode()
        {
            string path = @"C:UsersLinDesktop机试2xmlookstore.xml";

            XmlDocument doc = new XmlDocument();
            doc.Load(path);

            XmlElement root = doc.DocumentElement;     　　　　　　 //获取根节点
            XmlElement newBook = doc.CreateElement("book");        //创建新的book节点
            newBook.SetAttribute("ISBN", "112-1123");             //设置新 book 节点的属性，参数1为属性名 ，参数2为属性值
            XmlElement title = doc.CreateElement("title");    //创建title 节点
            title.InnerText = "自学自导3";                     //为title 节点赋值
            newBook.AppendChild(title);                      //将title节点附加到 新book节点后
            XmlElement author = doc.CreateElement("author");
            author.InnerText = "自己";
            newBook.AppendChild(author);
            XmlElement price = doc.CreateElement("price");
            price.InnerText = "13";
            newBook.AppendChild(price);

            root.AppendChild(newBook);                             //将newBook添加到xml文件的最后
            doc.Save(path);
        }

读取到指定 节点 ，并修改值：

//读取到 book 中 author 为“朱少民”所在的 book 节点
//    朱少民  用单引号进行引用
   XmlNode node3 = doc.SelectSingleNode("bookstore/book[author='朱少民']");

//修改节点的属性
  node3.Attributes["ISBN"].InnerText = "12345670008";
  doc.Save(@"C:UsersLinDesktop机试2xmlookstore.xml");

//修改节点
  node3.ChildNodes[0].InnerText="朱少民的书";
  doc.Save(@"C:UsersLinDesktop机试2xmlookstore.xml");

 写入到 txt 文件中：

        private static void writeText(List<BookModel> books)
        {
          //文件不存在时，自动创建
            using (StreamWriter sr = new StreamWriter(@"C:UsersLinDesktop机试2xml	est.txt"))
            {
                foreach (BookModel book in books)
                {
                    sr.WriteLine("{0},{1},{2}", book.BookName, book.BookAuthor, book.BookPrice);
                    Console.WriteLine("{0},{1},{2}", book.BookName, book.BookAuthor, book.BookPrice);
                }
            }
        }