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Web2.0时代，RSS你会用了吗？RSS技术实现总结 | |
| 阅读 207 次 更新时间：2008/8/6 | |
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不管怎样，它来了，你准备好了吗？ 说到Web2.0，就会提到Blog、TAG、SNS、RSS、wiki这些软件应用和xml、ajax等这些新理论和技术实现。 RSS毋容置疑就是其重要的应用之一。 那么什么是RSS？它到底有什么用呢？ RSS是站点与站点之间共享内容的一种简易方式(也称为“聚合内容”)，通常被用于新闻和其他按顺序排列的网站，例如Blog网站。网站提供RSS输出，有利于让用户发现网站内容的更新。网站用户可以在客户端借助于类似新闻资讯阅读器等支持RSS的新闻聚合工具软件，在不打开网站内容页面的情况下阅读支持RSS输出的网站内容。 RSS是基于XML的一种形式。并且所有的RSS文件都要遵守万维网联盟(W3C)站点发布的XML 1.0规范。具体格式可以查一下RSS 2.0规范，这里就不再重复粘贴了。 下面是我总结的几种RSS的技术实现代码： 1.在线生成RSS聚合页。 (1)创建Rss.aspx <%@ Page language="c#" Codebehind="Rss.aspx.cs" AutoEventWireup="false" Inherits="LiTianPing.Rss" %> 只留下这一行，其余的都删掉。 (2)后台代码实现方式1；Rss.aspx.cs private void Page_Load(object sender, System.EventArgs e) { Response.ContentType="text/xml"; Response.Write(GetRSS()); } /// <summary> /// 取得聚合文章 /// </summary> /// <returns></returns> public string GetRSS() { News t=new News();//自己的业务类 DataSet ds=t.GetListByClass(1);//根据类别得到数据 StringBuilder strCode=new StringBuilder(); strCode.Append("<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"yes\" ?>"); strCode.Append("<rss version=’’’’2.0’’’’ xmlns:dc=\"http://purl.org/dc/elements/1.1//""); strCode.Append(" xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback//" "); strCode.Append(" xmlns:wfw=\"http:/ wellformedweb.org/CommentAPI//" xmlns:slash=\"http://purl.org/rss/1.0/modules/slash//">"); strCode.Append("<channel>"); strCode.Append("<title>李天平RSSDemo</title>"); strCode.Append("<link>http://"+Request.ServerVariables["SERVER_NAME"]+"</link> "); strCode.Append("<description>天道酬勤</description> "); strCode.Append("<copyright>Copyright 2005</copyright> "); foreach(DataRow row in ds.Tables[0].Rows) { string Id=row["Id"].ToString(); string title=row["title"].ToString(); string description=row["description"].ToString(); string pubdate=row["pubdate"].ToString(); string ClassId=row["ClassId"].ToString(); //string author=row["author"].ToString(); strCode.Append("<item>"); strCode.Append("<title>"+title+"</title>"); strCode.Append("<link>http://"+Request.ServerVariables["SERVER_NAME"]+"/NewsShow.aspx?ID="+Id+"</link>"); strCode.Append("<subject>"+description+"</subject>"); strCode.Append("<description><![CDATA["+description+"]]></description>"); strCode.Append("<PubDate>"+pubdate+"</PubDate>"); strCode.Append("<category>"+ClassId+"</category>"); strCode.Append("</item>"); } strCod .Append("</channel>"); strCode.Append("</rss>"); return strCode.ToString(); } (3) XmlTextWriter实现方式2；Rss.aspx.cs string xmlDoc="rss.xml"; private void Page_Load(object sender, System.EventArgs e) { xmlDoc=Server.MapPath(".")+xmlDoc; GetRSS2(); XmlDocument doc= new XmlDocument(); doc.Load(xmlDoc); Response.ContentType = "text/xml"; doc.Save(Response.Output); } /// <summary> /// 取得聚合文章 /// </summary> /// <returns></returns> public void GetRSS2() { News t=new News(); DataSet ds=t.GetListByClass(1); XmlTextWriter writer = new XmlTextWriter(xmlDoc,Encoding.UTF8); writer.Formatting = Formatting.Indented; writer.WriteStartDocument(true); writer.WriteComment("RSS页的实现"); writer.WriteStartElement("rss"); writer.WriteAttributeString("version","2.0"); writer.WriteStartElement("channel"); writer.WriteStartElement("title"); writer.WriteString("李天平RSSDemo"); writer.WriteEndElement(); writer.WriteStartElement("link"); writer.WriteString("http://"+request.servervariables["server_name/"]); writer.WriteEndElement(); writer.W iteStartElement("description"); writer.WriteString("天道酬勤"); writer.WriteEndElement(); writer.WriteStartElement("copyright"); writer.WriteString("Copyright 2005"); writer.WriteEndElement(); writer.WriteStartElement("language"); writer.WriteString("zh-cn"); writer.WriteEndElement(); foreach(DataRow row in ds.Tables[0].Rows) { string Id=row["Id"].ToString(); string title=row["title"].ToString(); string description=row["description"].ToString(); string pubdate=row["pubdate"].ToString(); string ClassId=row["ClassId"].ToString(); //string author=row["author"].ToString(); writer.WriteStartElement("item"); writer.WriteStartElement("title"); writer.WriteString(title); writer.WriteEndElement(); writer.WriteStartElement("link"); writer.WriteString(" writer.WriteCData(description); writer.WriteEndElement(); writer.WriteStartElement("pubDate"); writer.WriteString(pubdate); writer.WriteEndElement(); writer.WriteStartElement("category"); writer.WriteString(ClassId); writer.WriteEndElement(); writer.WriteEndElement(); } writer.WriteEndElement(); writer.WriteEndElement(); & bsp;writer.Flush(); writer.Close(); } 2.在线RSS阅读获取。 页面代码： <P style="FONT-SIZE: 11px"> Feed种子：<asp:TextBox id="FeedUrl" runat="server" Width="440px"></asp:TextBox><BR> 显示条数：<asp:TextBox id="Num" runat="server" Width="48px"></asp:TextBox></P> <P style="FONT-SIZE: 11px"> <asp:Button id="GetFeed" runat="server" Text="获得RSS"></asp:Button><BR> <BR> <asp:Label id="RssFeed" runat="server"></asp:Label></P> 后台代码： /// <summary> /// 获得要显示的Feed种子数据 /// </summary> /// <param name="RssUrl"></param> /// <param name="showNewsCount"></param> /// <returns></returns> public string LoadRSS(string RssUrl, int showNewsCount) { string strRssList = ""; string strMsg; try { XmlDocument objXMLDoc = new XmlDocument(); objXMLDoc.Load(RssUrl); XmlNodeList objItems = objXMLDoc.GetElementsByTagName("item"); if(showNewsCount > 30) showNewsCount = 10; if(showNewsCount < 1) showNewsCount = objItems.Count; & bsp; string title=""; string link=""; int i; if(objXMLDoc.HasChildNodes == true) { i = 1; foreach(XmlNode objNode in objItems) { if(i<=showNewsCount) { if(objNode.HasChildNodes == true) { XmlNodeList objItemsChild = objNode.ChildNodes; foreach(XmlNode objNodeChild in objItemsChild) { switch(objNodeChild.Name) { case "title": title = objNodeChild.InnerText; break; case "link": link = objNodeChild.InnerText; break; } } i = i+1; strRssList += "<a href=" + link +" target=_blank>" + title + "</a><br>"; } & bsp; } } } strMsg = strRssList; } catch { strMsg = "RSS Feed 源数据出错！"; } return strMsg; } //获取按钮,获取指定RSS private void GetFeed_Click(object sender, System.EventArgs e) { if(FeedUrl.Text == "")//RSS地址 { RssFeed.Text = "信息源不能为空，您可刷新重试或联系管理员！"; return ; } RssFeed.Text = LoadRSS(FeedUrl.Text,Convert.ToInt32(Num.Text)); //获取指定数目 } 3.无刷新动态更新的在线RSS阅读获取 <%@ Page language="c#" Codebehind="XmlHttp.aspx.cs" AutoEventWireup="false" Inherits="LiTianPing.XmlHttp" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" > <HTML> <HEAD> <title>XmlHttp</title> <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1"> <meta name="CODE_LANGUAGE" Content="C#"> <meta name="vs_defaultClientScript" content="JavaScript"> <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5"> <style>td { font-size: 9pt} </style> <script> <!-- var oDiv var xh function getXML() { xh =new ActiveXObject("Microsoft.XMLHTTP"); oDiv = document.getElementById("rssitem"); oDiv.style.display= ""; try { //如果是本地改成下面语句直接读取 //xh.open("GET","/Rss.aspx",false); xh.open("GET","Http://ltp.cnblogs.com/Rss.aspx",false); xh.send(null); loadData(xh,oDiv); } catch(e) { error(oDiv); } } function loadData(xh,oDiv) { if (xh.readyState == 4) { xml = xh.responsexml; var i; var nodes = xml.selectNodes("/rss/channel/item"); var bloglink = xml.selectSingleNode("/rss/channel/link").text; oDiv.innerHTML = ""; var html; for(i=0;i<nodes.length;i++) { html += "<div >"; html += " <div >"; html += " <a class=font1 href=’’’’" +nodes[i].selectSingleNode("link").text + "’’’’ target=’’’’_blank’’’’>" + nodes[i].selectSingleNode("title").text +"</a><BR><BR>"; html += &qu t; </div>"; html += " <div >"; html += " " +nodes[i].selectSingleNode("description").text; html += " </div>" //html += " </div>"; html += "</div><hr>"; } oDiv.innerHTML = html; } else { error(oDiv); } } function error(oDiv) { oDiv.innerHTML = "载入失败"; } --> </script> </HEAD> <body MS_POSITIONING="GridLayout" onload="window.setTimeout(’’’’getXML()’’’’,200);"> <form id="Form1" method="post" runat="server"> <div align=center> <table cellpadding="0" cellspacing="0" border="0" width="80%"> <tr> <td> <div id="rssitem" style="WIDTH:80%">数据载入中...</div> </td> </tr> </table> </div> </form> </body> </HTML> | |
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