RSS 订阅功能的实现

 很多站点多会用到RSS订阅功能，今天写了个，留个笔记。

 我们可以用.aspx,.ashx文件构建xml文件，输出xml 可以通过 XmlTextWriter实例化来输出，也可以直接输出。

1.利用XmlTextWriter输出

  

    public String uid = "461";
    public String UserInfo = String.Empty;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Request.QueryString["id"] != null && Request.QueryString["id"].ToString() != "")
        {
            uid = Request.QueryString["id"].ToString();
        }
        Response.ContentType = "application/rss+xml";
        Response.ContentEncoding = Encoding.UTF8;
        XmlTextWriter rsswriter = new XmlTextWriter(Response.OutputStream, Encoding.UTF8);

        WriteRssOpening(rsswriter);
        WriteRssBody(rsswriter);
        WriteRssEnding(rsswriter);
        rsswriter.Flush();
        Response.End();
    }


    /// <summary>
    ///  信息标题
    /// </summary>
    /// <param name="rsswriter"></param>
    private void WriteRssOpening(XmlTextWriter rsswriter)
    {
        UserBasicModelInfo info = UserBasic.GetBasicList(uid);
        rsswriter.WriteStartElement("rss");
        rsswriter.WriteAttributeString("version", "2.0");
        rsswriter.WriteStartElement("channel");
        rsswriter.WriteElementString("title", info.TrueName+"的官方博客");
        rsswriter.WriteElementString("link", Application["Url"] + "/Rss.aspx?id=" + uid + "");
        rsswriter.WriteElementString("description", info.TrueName + "的官方博客");
    }

    /// <summary>
    ///  信息整体
    /// </summary>
    /// <param name="rsswriter"></param>
    private void WriteRssBody(XmlTextWriter rsswriter)
    {
        DataTable GetDate = wdxt_Common.GetSomeData.GetDataNum("VW_NEWLOG", "*", "LOGSEECOMPETENCE=1 and userinfoid=" + uid + "", "addtime desc ", 100).Tables[0];

        foreach (DataRow rssitem in GetDate.Rows)
        {
            rsswriter.WriteStartElement("item");
            rsswriter.WriteElementString("title", rssitem["logtitle"].ToString());
            rsswriter.WriteElementString("author", rssitem["TRUENAME"].ToString());
            rsswriter.WriteElementString("link", ""+Application["Url"]+"/Log/show_" + rssitem["logid"].ToString() + "_6");
            rsswriter.WriteElementString("description", rssitem["logcontent"].ToString());
            rsswriter.WriteElementString("pubDate", rssitem["addtime"].ToString());
            rsswriter.WriteEndElement();
        }
    }

    private void WriteRssEnding(XmlTextWriter rsswriter)
    {
        rsswriter.WriteEndElement();
        rsswriter.WriteEndElement();
    }   

2. 直接输出XML

  

protected String uid = String.Empty;
    protected void Page_Load(object sender, EventArgs e)
    {
        Response.Clear();
        uid = HttpContext.Current.Request.QueryString["id"].ToString();
       
        Response.ContentType = "text/xml";
        Response.Charset = "GB2312";
        Response.Write(GetRSS());
    }

    #region
    /// <summary>
    /// 取得聚合文章
    /// </summary>
    public string GetRSS()
    {
        UserBasicModelInfo info = UserBasic.GetBasicList(uid);

        DataSet ds =  wdxt_Common.GetSomeData.GetDataNum("VW_NEWLOG", "*", "LOGSEECOMPETENCE=1 and userinfoid=" + uid + "", "addtime desc ", 100);
        String strRSS = "<?xml version=\"1.0\" encoding=\"gb2312\" ?><rss version=\"2.0\">";
        strRSS += "<channel>";
        strRSS += "<title>" + info.TrueName + "的博客</title>";
        strRSS += "<link>" + Application["Url"] + "/Myspace/Space/Rss1.aspx?id=" + uid + "</link>";
        strRSS += "<description></description>";
        for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
        {
            string Logid = ds.Tables[0].Rows[i]["logid"].ToString();
            string LogContent = ds.Tables[0].Rows[i]["LogContent"].ToString();
            string Title = ds.Tables[0].Rows[i]["logtitle"].ToString();
            String LogAddTime = ds.Tables[0].Rows[i]["Addtime"].ToString();
            string truename = ds.Tables[0].Rows[i]["TrueName"].ToString();

            strRSS += "<item>";
            strRSS += "<title>" + Title + "</title>";
            strRSS += "<link>" + Application["Url"] + "/Blog/info/" + Logid + "</link>";
            strRSS += "<pubDate>" + LogAddTime + "</pubDate>";
            strRSS += "<copyright>" + truename + "</copyright>";
            strRSS += "<description><![CDATA[" + LogContent + "]]></description>";
            strRSS += "</item>";
        }
        strRSS += "</channel>";
        strRSS += "</rss>";
        return strRSS;
    }
    #endregion

参考：1.  微软的CSASPNETRssFeeds

        2.  我的源码

        3. 可能还要为站点添加到别的网站的RRS链接，可以看看博客园的。