C#实现XML文档的增删改查

1、 创建实例XML文件（Books.xml）

  
    
    Giada De Laurentiis
    2005
    30.00
  
  
    
    J K. Rowling
    2005
    29.99
  
  
    
    James McGovern
    Per Bothner
    Kurt Cagle
    James Linn
    Vaidyanathan Nagarajan
    2003
    49.99
  
  
    
    Erik T. Ray
    2003
    39.95
  

2、 创建图书信息实体类（BookInfo.cs）

public class BookInfo
{
    /// 

    /// 图书ID
    /// 
    public int BookId { set; get; }

    /// 

    /// 图书名称
    /// 
    public string Title { set; get; }

    /// 

    /// 图书分类
    /// 
    public string Category { set; get; }

    /// 

    /// 图书语言
    /// 
    public string Language { set; get; }

    /// 

    /// 图书作者
    /// 
    public string Author { set; get; }

    /// 

    /// 出版时间
    /// 
    public string Year { set; get; }

    /// 

    /// 销售价格
    /// 
    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);
        }
    }

    /// 

    /// 获取图书列表(查)
    /// 
    /// 参数条件
    /// 图书列表
    public List GetBookInfoList(BookInfo param)
    {
        List bookInfoList = new List();
        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;
    }

    /// 

    /// 增加图书信息（增）
    /// 
    /// 
    /// 
    public bool AddBookInfo(BookInfo param)
    {
        bool result = false;
        XmlNode root = _booksXmlDoc.SelectSingleNode("bookstore");  //查找
        //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;
    }

    /// 

    /// 修改图书信息（改）
    /// 
    /// 
    /// 
    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;
    }

    /// 

    /// 删除图书信息（删）
    /// 
    /// 
    /// 
    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;
    }

}