RSS订阅的实例

1.新建一用户控件RSSCommonListModule.ascx,读取RSS数据
ASPX:

 1 <table width="100%" id="tb<%=this.ClientID%>" style="display:none"> 
 2 <tr>
 3 <td width="50%">
 4 <ul class="ul_list2">
 5     <asp:repeater id="rpList" Runat="server">
 6         <ItemTemplate>
 7             <li>
 8                 <span><%# DataBinder.Eval(Container.DataItem,"pubDate","{0:d}")%><asp:Literal ID="litNewImg" Runat="server" Visible="False"></asp:Literal></span>
 9                 <A href='<%# DataBinder.Eval(Container.DataItem,"link")%>' target="_blank" title="<%# DataBinder.Eval(Container.DataItem,"title").ToString()%>">
10                     <%# GetStringByLen(DataBinder.Eval(Container.DataItem,"title").ToString(),19)%>
11                     
12                 </A>
13                 
14                 
15                 <asp:Literal ID="litPubDate" Runat="server" Visible="False" Text='<%# DataBinder.Eval(Container.DataItem,"pubDate","{0:d}")%>'></asp:Literal>
16                 <asp:Literal ID="litTD" Runat="server"></asp:Literal>
17                 </li>
18         </ItemTemplate>
19     </asp:repeater>
20 </ul>
21 </td>
22 </tr>
23 </table>

CS:

    using System;
    using System.Data;
    using System.Drawing;
    using System.Web;
    using System.Web.UI.WebControls;
    using System.Web.UI.HtmlControls;
    using NRss;
    using System.Text;
    using System.IO;

    public class RssCache
    {
        public DateTime lastFlashDT;
        public Rss rss;
        public RssChannelItemCollection showdata;
    }
    /// <summary>
    ///        RSSCommonListModule 的摘要说明。
    /// </summary>
    public class RSSCommonListModule : System.Web.UI.UserControl
    {
        protected System.Web.UI.WebControls.Repeater rpList;

        private  string _cssclass;
        private string _morelink;
        
        
        public string Cssclass
        {
            get{return _cssclass; }
            set{_cssclass=value;}
        }

        public string MoreLink
        {
            get{return _morelink; }
            set{_morelink=value;}
        }

        public string RssAddress
        {
            get
            {
                return ViewState["__RssAddress__"]==null?"":ViewState["__RssAddress__"].ToString();
            }
            set
            {
                ViewState["__RssAddress__"] =value;
            }
        }

        public string RssTitle
        {
            get
            {
                return ViewState["__RssTitle__"]==null?"":ViewState["__RssTitle__"].ToString();
            }
            set
            {
                ViewState["__RssTitle__"] =value;
            }
        }

        private int _contentcnt = 0;
        public int ContentCnt
        {
            get
            {
                return _contentcnt;
            }
            set
            {
                _contentcnt = value;
            }
        }

        private int _maxcontentcnt = 0;
        public int MaxContentCnt
        {
            get
            {
                return _maxcontentcnt;
            }
            set
            {
                _maxcontentcnt = value;
            }
        }

        private int _reflashtime = 10;
        public int ReflashTime
        {
            get 
            {
                return _reflashtime;
            }
            set
            {
                _reflashtime = value;
            }
        }

        public RssCache RssData
        {
            get
            {
                return Cache["rssdata_"+this.ClientID]==null?null:(Cache["rssdata_"+this.ClientID] as RssCache);
            }
            set
            {
                Cache["rssdata_"+this.ClientID] = value;
            }
        }
        protected string AppPath
        {
            get
            {
                return "";
            }
        }

        private void Page_Load(object sender, System.EventArgs e)
        {
            if(!IsPostBack)
            {
                this.BindList();
            }
        }
        private void BindList()
        {
            RssReader reader;
            //Rss rss;
            
            if(RssAddress==null||RssAddress=="")
                return;
            reader = new RssReader(RssAddress);
            
            try
            {

                if(this.RssData==null)
                {
                    this.RssData = new RssCache();
                    this.RssData.rss = reader.Read();
                    this.RssData.lastFlashDT = DateTime.Now;

                    int itemCnt = MaxContentCnt;

                    ContentCnt = this.RssData.rss.Channel.Items.Count;

                    if(MaxContentCnt>ContentCnt)
                        itemCnt = ContentCnt;
                
                    this.RssTitle = this.RssData.rss.Channel.Title.Trim();
                

                    RssChannelItemCollection data = new RssChannelItemCollection();
                        
                    for(int i=0;i<itemCnt;i++)
                    {
                        data.Add(this.RssData.rss.Channel.Items[i]);
                    }
                    this.RssData.showdata = data;

                }
                else
                {
                    DateTime now = DateTime.Now;
                    DateTime Last = this.RssData.lastFlashDT.AddMinutes(this.ReflashTime);
                    //如果超过了设定时间则重新加载
                    if(now>Last)
                    {
                        this.RssData.rss = reader.Read();
                        this.RssData.lastFlashDT = DateTime.Now;

                        int itemCnt = MaxContentCnt;

                        ContentCnt = this.RssData.rss.Channel.Items.Count;

                        if(MaxContentCnt>ContentCnt)
                            itemCnt = ContentCnt;
                
                        this.RssTitle = this.RssData.rss.Channel.Title.Trim();
                

                        RssChannelItemCollection data = new RssChannelItemCollection();
                        
                        for(int i=0;i<itemCnt;i++)
                        {
                            data.Add(this.RssData.rss.Channel.Items[i]);
                        }
                        this.RssData.showdata = data;
                    }
                }

                ContentCnt = this.RssData.rss.Channel.Items.Count;
            
            

                
                
                if(this.RssData.showdata!=null)
                {
                    this.rpList.DataSource =this.RssData.showdata;
                    this.rpList.DataBind();
                }
            }
            catch(Exception ex)
            {
                reader.Close();
            }
            finally
            {
                reader.Close();
            }

            //            
            //            DataSet ds = new DataSet();
            //            StreamReader   srReadGbkXml   =   new   StreamReader(RssAddress,   System.Text.Encoding.GetEncoding("gb2312"));   
            //
            //            ds.ReadXml(srReadGbkXml);
            //            
            //
            //            this.rpList.DataSource = ds.Tables["item"];
            //            this.rpList.DataBind();
            
        }

        private void rpList_ItemDataBound(object sender, System.Web.UI.WebControls.RepeaterItemEventArgs e)
        {
            Literal litNewImg= (Literal) e.Item.FindControl("litNewImg");
            Literal litTD= (Literal) e.Item.FindControl("litTD");
            Literal litPubDate= (Literal) e.Item.FindControl("litPubDate");
            
            
            DateTime dt1=DateTime.Now;
            //            if(drv["CreateDt"].ToString().Trim().Substring(0,10)==dt.ToString().Trim().Substring(0,10))
            //                litNew.Text="<font color='red'>New</font>";    
            DateTime dt=DateTime.Parse(litPubDate.Text.ToString().Trim());
            TimeSpan ts=dt1-dt;
            int day=ts.Days;
            if(day<Convert.ToInt32(System.Configuration.ConfigurationSettings.AppSettings["ContentIsNewLimitDay"]))
                litNewImg.Text="<img src='"+this.AppPath+"Images/new3.gif'>";    
            int m = ContentCnt/2;
            if((ContentCnt%2)!=0)
                m = (ContentCnt+1)/2;
            if(m>10)
                m=10;
            if((e.Item.ItemIndex+1)==m)
            {
                litTD.Text="</ul></td><td><ul class=\"ul_list2\">";
            }
        }
        public string GetStringByLen(string str,int len)
        {
            
            if(str.Length>len)
                str=str.Substring(0,len);
            return str;                
        }

2.新建Web窗体rss_news.aspx,将用户控件拖入,添加RSS地址

<uc1:RSSCommonListModule id="RSSCommonListModule1" runat="server" RssAddress="http://news.google.cn/nwshp?oe=UTF-8&tab=wn&ned=ccn&output=rss"
                    MoreLink="#" MaxContentCnt="20" ReflashTime="30"></uc1:RSSCommonListModule>

3.主页上插入个IFRAME,链接至rss_news.aspx

<div id="div_rss_news1_msg" align="center"><font color="red">新闻数据加载中请稍候!</font></div>
                        <iframe src="rss_news1.aspx" frameborder="0" width="750" align="middle" id="news1" onreadystatechange="hideMsg('div_rss_news1_msg')">
                        </iframe>