从Xml文件读取帮助

Question

I have Xml file like this:

<store>
  <book id="A1" name="WEB" price="10"/>
  <book id="b1" name="C#" price="15"/>
  <book id="c1" name="DOT" price="12"/>
  <book id="d1" name="JAVA" price="20"/>
  <book id="e1" name="C" price="13"/>
 </store>

I have book Id want to get book name and price if its new book need to create new element and default id only. please help me on this

I am using .Net 2.0 c sharp

Answer 1

How about simply using Linq2XML? This gives you easy query access to your data - find, sort, insert, delete....

Answer 2

There's actually two parts to your problem that I can.

1. Get a book object from known Id
2. Create a new book object

To retrieve the object:

 public class Book
 {
    public Book(string id, string name, decimal price)
    {
        Id = id;    
        Name = name;
        Price = price;
    }
    public string Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
 }

To load the book with known Id into the object:

XmlDocument xmlDocument = new XmlDocument();

xmlDocument.Load(_path);

XmlNode xmlNode = xmlDocument.SelectSingleNode(@"//book[@id='" + id + "']");

return xmlNode == null ? new Book(id, string.Empty, 0) : new Book(id, xmlNode.Attributes["name"].Value, decimal.Parse(xmlNode.Attributes["price"].Value));

To create a new book element:

XmlDocument xmlDocument = new XmlDocument();

xmlDocument.Load(_path);

XmlElement newBook = xmlDocument.CreateElement("book");
newBook.SetAttribute("id", book.Id);
newBook.SetAttribute("name", book.Name);
newBook.SetAttribute("price", book.Price.ToString());

xmlDocument.DocumentElement.AppendChild(newBook);

xmlDocument.Save(_path);

Where _path is the path to your XML document.

I hope this helps. Also remember that XmlDocument is an in-memory or cached tree representation of an XML document. It is somewhat resource-intensive, if you have a large XML document and not enough memory to consume, use XmlReader and XmlWriter for better performance.