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。
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
代码语言：js复制 <?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
代码语言：js复制 public class Category
{
public int cid { get; set; }
public string title { get; set; }
}
3.用linq读取
代码语言：js复制
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
代码语言：js复制<%@ 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;
}
}
}
