CaseStudy(showcase)数据篇-从XML中获取数据

做silvelight也有一段时间了，相册、游戏，刚刚完成的showcase这个小程序算是一个阶段了。这里就以showcase这个项目来做一下CaseStudy。

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：

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>

定义实体类

     public class Category     {         public int cid { get; set; }         public string title { get; set; }     }

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;

}

作者：nasa

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