ASP.NET的SEO：Linq to XML---网站地图和RSS Feed

本系列目录

网站地图的作用是让搜索引擎尽快的，更多的收录网站的各个网页。
   
这里我们首先要明白一个基本的原理，搜索引擎的爬行方式。整个互联网就像一张纵横交错的“网”：网的各个节点就是各个网页，而各个网页之间通过url相互连接。蜘蛛可以从一个网页出发，通过该网页上的url，爬到另一个网页；再通过另一个网页上的url，再爬到更多的网页……，以此类推。但如果是一个新发布的网站，可能就没有其他url指向它，那么它就永远不会被“爬到”（收录）。为了解决这个问题，新站可以自己主动向搜索引擎提交url，申请蜘蛛前来抓取（Google申请网址：），但申请时一般只会提交一个主页的url。

为了让所有的url（尤其是动态生成的）都能被蜘蛛快捷便利的检索到，我们就需要提供一个全面完整、架构清晰和更新及时的网站地图。（ 网站地图的更多信息）。

和处理重复内容的robots.txt文件，我们通过.ashx文件来生成一个基于sitemaps.org的xml格式的网站地图。网站地图生成之后，我们就可以向Google等搜索引擎提交。大量的文章证实，提交网站地图将极大的提高网站的收录速度和深度。其他几乎所有的SEO方法，都有可能效果难以证实、失效甚至带来副作用，但提交网站地图除外！

 

Linq to XML为我们带来了近乎完美的操作体验。

WebSite

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

using System;
using System.Web;
using System.Xml;
using System.Xml.Linq;
using System.Linq;

public   class website : IHttpHandler {
   
    public   void ProcessRequest (HttpContext context) {

        context.Response.ContentType =   " text/xml " ;

        // 文件的声明信息，第第三个参数standalone的值yes 表示这个 XML 文档是自包含的(self-contained)而不依赖于外部所定义的一个 DTD.
        XDeclaration declaration =   new XDeclaration( " 1.0 " , " UTF-8 " , " yes " );
        context.Response.Write(declaration);
       
        // XML文件的命名空间
        XNamespace ns =   " http://www.google.com/schemas/sitemap/0.84 " ;
        XElement siteMap =   new XElement(ns +   " urlset " );

        string fixedUrl =   " http://www.freeflying.com/article " ;
        string wholeUrl =   string .Empty;
       
        // 循环取出数据，转换成XML节点
        foreach (var item in Articles.GetArticles())
        {
            XElement url =   new XElement( " url " );

            wholeUrl =   string .Format( " {0}?id={1}&catelog={2} " ,fixedUrl,item.ID,item.Catelog);
            XElement loc =   new XElement( " loc " , wholeUrl);
            XElement lastmod =   new XElement( " lastmod " , item.LastMod.AddDays( - 23 ).ToShortDateString());
            XElement changefreq =   new XElement( " changefreq " , item.Frequency);
            XElement priority =   new XElement( " priority " , item.Weight);

            url.Add(loc, lastmod, changefreq, priority);

            siteMap.Add(url);
        }

       
       
        // 最后输出整个xml文件
        context.Response.Write(siteMap);
    }
 
    public   bool IsReusable {
        get {
            return   false ;
        }
    }

}

 

同样还将使用到xml技术的还有RSS

RSS

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

using System;
using System.Web;
using System.Xml;
using System.Xml.Linq;


public   class rss : IHttpHandler {
   
    public   void ProcessRequest (HttpContext context) {
        context.Response.ContentType =   " text/xml " ;

        context.Response.Write( " <?xml version=\ " 1.0 \ " encoding=\ " UTF - 8 \ " ?> " );

        XElement rssFeed =   new XElement( " rss " , new XAttribute( " version " , " 2.0 " ));

        string fixedUrl =   " http://www.freeflying.com/article " ;
        string wholeUrl =   string .Empty;

        XElement channel =   new XElement( " channel " ,
            new XElement( " title " , " freeflying " ),
            new XElement( " link " , fixedUrl),
            new XElement( " description " , " the website for dream flying freely " ),
            new XElement( " pubDate " ,DateTime.Now.ToString())
            );
       
       
        foreach (var article in Articles.GetArticles())
        {
            XElement item =   new XElement( " item " );

            XElement title =   new XElement( " title " , article.Title);

            wholeUrl =   string .Format( " {0}?id={1}&catelog={2} " , fixedUrl, article.ID, article.Catelog);
            XElement link =   new XElement( " link " , wholeUrl);

            XElement description =   new XElement( " description " , article.Description);

            XElement pubDate =   new XElement( " pubDate " , article.LastMod.ToString());

            item.Add(title,link,description,pubDate);

            channel.Add(item);
        }

        rssFeed.Add(channel);

        context.Response.Write(rssFeed);

    }
 
    public   bool IsReusable {
        get {
            return   false ;
        }
    }
   

}

　　　

模拟数据

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Web.UI.MobileControls;
using System.Collections.Generic;

///   <summary>
/// Summary description for Articles
///   </summary>
public   class Articles
{
    public Articles()
    {
        //
        // TODO: Add constructor logic here
        //
    }

    public   static List < Article > GetArticles()
    {
        return   new List < Article > (){
            new Article( 234 , " blog " , DateTime.Now.AddDays( - 23 ), Freq.none, 0.8 , " asp.net seo " , " articles about SEO in asp.net " ),
            new Article( 267 , " blog " , DateTime.Now.AddDays( - 245 ), Freq.daily, 0.6 , " ado.net pro " , " about the dataset usage " ),
            new Article( 653 , " news " , DateTime.Now.AddDays( - 45 ), Freq.daily, 1 , " CLR via C# " , " notebook about this book " )
        };
    }


}

public   class Article
{
    public   int ID;
    public   string Catelog;
    public DateTime LastMod;
    public   double Weight;
    public Freq Frequency;
    public   string Title;
    public   string Description;

    public Article( int id, string catelog, DateTime lastMod, Freq frequency, double weight, string title, string description)
    {
        ID = id;
        Catelog = catelog;
        LastMod = lastMod;
        Weight = weight;
        Frequency = frequency;
        Title = title;
        Description = description;
    }
}

public   enum Freq
{
    none =   1 ,
    daily =   2 ,
    weekly =   3 ,
}