数据篇——从XML中获取数据

这个项目我的后台用的是asp.net开发。由于规模比较小我的数据层用的是subsonic。用它来做开发会比较敏捷。

这一回我选择的数据方式是asp.net生成xml，用silverlight中的Linq来实例化成具体的类。

这里我以读取类别信息为例子，分为3步：

1. 定义xml
   <?xml version="1.0" encoding="utf-8" ?>
   <categories>
   <category><cid>2</cid><title>Dumex</title></category>
   <category><cid>1</cid><title>MySVW</title></category>
   <category><cid>3</cid><title>Microsoft</title></category>
   </categories>
2. 定义实体类 
        public class Category
       {
           public int cid { get; set; }
           public string title { get; set; }
       }
3. 用linq读取
               WebClient client = new WebClient();
               client.DownloadStringAsync(new Uri(HtmlPage.Document.DocumentUri, "category.ashx"));
               client.DownloadStringCompleted += new DownloadStringCompletedEventHandler(client_DownloadStringCompleted);
              
           void client_DownloadStringCompleted(object sender, DownloadStringCompletedEventArgs e)
           {
               XmlReader reader = XmlReader.Create(new StringReader(e.Result));
               XDocument document = XDocument.Load(reader);
               var categories = from c in document.Descendants("category")
                                select new Category
                                {
                                    cid = int.Parse(c.Element("cid").Value),
                                    title = c.Element("title").Value
                                };
               //todo
           }

在这里我选用了ashx来配合subsonic生成xml文件

<%@ WebHandler Language="C#" Class="category" %>

using System;
using System.Web;
using System.Text;

public class category : IHttpHandler {
    StringBuilder sb = new StringBuilder();
    string templateStr = "<category>" +
                            "<cid>{0}</cid>" +
                            "<title>{1}</title>" +
                            "</category>";
    public void ProcessRequest (HttpContext context) {
        context.Response.ContentType = "text/xml";
        SC.CategoryCollection cc = new SC.CategoryCollection();
        SubSonic.Query query = SC.Category.Query().ORDER_BY("sortid", "desc");
        cc.LoadAndCloseReader(query.ExecuteReader());
        sb.AppendLine("<?xml version=\"1.0\" encoding=\"utf-8\" ?>");
        sb.AppendLine("<categories>");
        for (int i = 0; i < cc.Count; i++) {
            sb.AppendLine(string.Format(templateStr, cc[i].Id, cc[i].Title));
        }
        sb.AppendLine("</categories>");
        context.Response.Write(sb.ToString());
    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }

}

出处：蓝色理想
责任编辑：moby

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