C#实现XML文档的增删改查

小灰灰 2021-09-12 08:44 303阅读 0赞

**1、 创建实例XML文件（Books.xml）**

<?xml version="1.0" encoding="iso-8859-1"?>
    <bookstore>
      <book id="1" category="COOKING">
        <title lang="en">Everyday Italian</title>
        <author>Giada De Laurentiis</author>
        <year>2005</year>
        <price>30.00</price>
      </book>
      <book id="2" category="CHILDREN">
        <title lang="en">Harry Potter</title>
        <author>J K. Rowling</author>
        <year>2005</year>
        <price>29.99</price>
      </book>
      <book id="3" category="WEB">
        <title lang="en">XQuery Kick Start</title>
        <author>James McGovern</author>
        <author>Per Bothner</author>
        <author>Kurt Cagle</author>
        <author>James Linn</author>
        <author>Vaidyanathan Nagarajan</author>
        <year>2003</year>
        <price>49.99</price>
      </book>
      <book id="4" category="WEB">
        <title lang="en">Learning XML</title>
        <author>Erik T. Ray</author>
        <year>2003</year>
        <price>39.95</price>
      </book>
    </bookstore>

**2、 创建图书信息实体类（BookInfo.cs）**

public class BookInfo
    {
        /// <summary>
        /// 图书ID
        /// </summary>
        public int BookId { set; get; }
    
        /// <summary>
        /// 图书名称
        /// </summary>
        public string Title { set; get; }
    
        /// <summary>
        /// 图书分类
        /// </summary>
        public string Category { set; get; }
    
        /// <summary>
        /// 图书语言
        /// </summary>
        public string Language { set; get; }
    
        /// <summary>
        /// 图书作者
        /// </summary>
        public string Author { set; get; }
    
        /// <summary>
        /// 出版时间
        /// </summary>
        public string Year { set; get; }
    
        /// <summary>
        /// 销售价格
        /// </summary>
        public decimal Price { set; get; }
    }

**3、 创建图书信息业务逻辑类（BookInfoBLL.cs）**

using System.Xml;    //引用相关文件

public class BookInfoBLL
    {
        private string _basePath = AppDomain.CurrentDomain.SetupInformation.ApplicationBase + @"/xml/Books.xml";  //XML文件路径
        private XmlDocument _booksXmlDoc = null;   //创建XML文档对象
    
        public BookInfoBLL() 
        {
            try
            {
                _booksXmlDoc = new XmlDocument(); //初始化XML文档对象
                _booksXmlDoc.Load(_basePath);     //加载指定的XML文档
            }
            catch (Exception ex)
            {
                throw new Exception("加载XML文档出错：" + ex.Message);
            }
        }
    
        /// <summary>
        /// 获取图书列表(查)
        /// </summary>
        /// <param name="param">参数条件</param>
        /// <returns>图书列表</returns>
        public List<BookInfo> GetBookInfoList(BookInfo param)
        {
            List<BookInfo> bookInfoList = new List<BookInfo>();
            string xPath = "bookstore/book"; //默认获取所有图书
            if (param.BookId != 0) //根据图书ID查询
            {
                xPath = String.Format("/bookstore/book[@id='{0}']", param.BookId);
            }
            else if (!String.IsNullOrEmpty(param.Category)) //根据图书类别查询
            {
                xPath = String.Format("/bookstore/book[@category='{0}']", param.Category);
            }
            else if (!String.IsNullOrEmpty(param.Title)) //根据图书名称查询
            {
                xPath = String.Format("/bookstore/book[title='{0}']", param.Title);
            }
    
            XmlNodeList booksXmlNodeList = _booksXmlDoc.SelectNodes(xPath);
            foreach (XmlNode bookNode in booksXmlNodeList)
            {
                BookInfo bookInfo = new BookInfo();
                bookInfo.BookId = Convert.ToInt32(bookNode.Attributes["id"].Value);  //获取属性值
                bookInfo.Category = bookNode.Attributes["category"].Value;
                bookInfo.Language = bookNode.SelectSingleNode("title").Attributes["lang"].Value; //获取子节点的属性值
                bookInfo.Title = bookNode.SelectSingleNode("title").InnerText;     //获取元素值
                bookInfo.Author = bookNode.SelectSingleNode("author").InnerText;
                bookInfo.Year = bookNode.SelectSingleNode("year").InnerText;
                bookInfo.Price = Convert.ToDecimal(bookNode.SelectSingleNode("price").InnerText);
                bookInfoList.Add(bookInfo);
            }
            return bookInfoList;
        }
    
        /// <summary>
        /// 增加图书信息（增）
        /// </summary>
        /// <param name="param"></param>
        /// <returns></returns>
        public bool AddBookInfo(BookInfo param)
        {
            bool result = false;
            XmlNode root = _booksXmlDoc.SelectSingleNode("bookstore");  //查找<bookstore>
            //创建节点
            XmlElement bookXmlElement = _booksXmlDoc.CreateElement("book");
            XmlElement titleXmlElement = _booksXmlDoc.CreateElement("title");
            XmlElement authorXmlElement = _booksXmlDoc.CreateElement("author");
            XmlElement yearXmlElement = _booksXmlDoc.CreateElement("year");
            XmlElement priceXmlElement = _booksXmlDoc.CreateElement("price");
    
            //给节点赋值
            bookXmlElement.SetAttribute("id", param.BookId.ToString());    
            bookXmlElement.SetAttribute("category", param.Category);
            titleXmlElement.InnerText = param.Title; //给节点添加元素值
            titleXmlElement.SetAttribute("lang", param.Language);//给节点添加属性值
            authorXmlElement.InnerText = param.Author;
            yearXmlElement.InnerText = param.Year;
            priceXmlElement.InnerText = param.Price.ToString();
    
            //AppendChild 将指定的节点添加到该节点的子节点列表的末尾
            bookXmlElement.AppendChild(titleXmlElement);
            bookXmlElement.AppendChild(authorXmlElement);
            bookXmlElement.AppendChild(yearXmlElement);
            bookXmlElement.AppendChild(priceXmlElement);
    
            root.AppendChild(bookXmlElement);
            _booksXmlDoc.Save(_basePath);
            result = true;
            return result;
        }
    
        /// <summary>
        /// 修改图书信息（改）
        /// </summary>
        /// <param name="param"></param>
        /// <returns></returns>
        public bool EditBookInfo(BookInfo param)
        {
            bool result = false;
            if(param.BookId>0)
            {
                string xPath = String.Format("/bookstore/book[@id='{0}']", param.BookId);
                XmlNode editXmlNode = _booksXmlDoc.SelectSingleNode(xPath);
                XmlElement editXmlElement = (XmlElement)editXmlNode;
                if (editXmlElement != null)
                { 
                    editXmlElement.Attributes["category"].Value = param.Category;
                    editXmlElement.SelectSingleNode("title").Attributes["lang"].Value = param.Language;
                    editXmlElement.SelectSingleNode("title").InnerText = param.Title;
                    editXmlElement.SelectSingleNode("author").InnerText = param.Author;
                    editXmlElement.SelectSingleNode("year").InnerText = param.Year;
                    editXmlElement.SelectSingleNode("price").InnerText = param.Price.ToString();
                    _booksXmlDoc.Save(_basePath);
                    result = true;
                }
            }
            return result;
        }
    
        /// <summary>
        /// 删除图书信息（删）
        /// </summary>
        /// <param name="param"></param>
        /// <returns></returns>
        public bool DeleteBookInfo(BookInfo param)
        {
            bool result = false;
            if (param.BookId > 0)
            {
                string xPath = String.Format("/bookstore/book[@id='{0}']", param.BookId);
                XmlNode delXmlNode = _booksXmlDoc.SelectSingleNode(xPath);
                if (delXmlNode != null)
                {
                    _booksXmlDoc.SelectSingleNode("bookstore").RemoveChild(delXmlNode);   //移除指定的子节点
                    _booksXmlDoc.Save(_basePath);
                    result = true;
                }
            }
            return result;
        }
    
    }