幻想曲.Net » linq

RssReader(Linq to xml)

幻想曲 — Sun, 17 Feb 2008 06:51:00 +0000

准确地说谈不上是一个阅读器，因为目前只显示rss源的标题

首先用一个xml文档来存储一些rss列表，结构如下：
幻想曲.Net http://www.yibin001.com http://www.yibin001.com/rss.axd 大脑门 http://www.iceapple.net http://www.iceapple.net/syndication.axd CnBlogs http://www.cnblogs.com http://www.cnblogs.com/rss BlueIdea http://bbs.blueidea.com/rss.php

enable属性表示该站点是否有效,false表示无效


展示页面中的dropdownlist数据源就来自于此 

选择一个rss源，点击read,显示


public class RssItem

{
    public RssItem()

    {

        //

        // TODO: Add constructor logic here

        //

    }

    public RssItem(string title, string url, DateTime date)

    {

        Title = title;

        URL = url;

        PubDate = date;

    }

    public string Title { get; set; }

    public string URL { get; set; }

    public DateTime PubDate { get; set; }

    public List GetList(string rssurl)

    {

        List list = new List();

        //try

        //{

            XDocument doc = XDocument.Load(rssurl);

            var feeds = from feed in doc.Descendants("item")

                        select new RssItem

                        {

                            PubDate = Convert.ToDateTime(feed.Element("pubDate").Value),

                            Title = feed.Element("title").Value,

                            URL = feed.Element("link").Value

                        };

            list = feeds.ToList();

        //}

        //catch

        //{
        //}

        return list;

    }

}

因暂无.net 3.5的空间，故无法放出演示了 
http://www.yibin001.comhttp://www.yibin001.com/wp-content/uploads/20080217/135729_RssReader.rar



Linq to sql之简单的分页
幻想曲 — Fri, 15 Feb 2008 09:20:00 +0000
费话不多说，主要是Linq中的Skip及Take这二个扩展方法


   int RecordCount = 0;

    int PageCount = 1;

    DataClassesDataContext data = new DataClassesDataContext();

    int SkipIndex = 0;

    private string _PageString = "";

    public string PageString

    {

        get {

            return _PageString;

        }

        set {

            _PageString = value;

        }

    }

    protected void Page_Load(object sender, EventArgs e)

    {

        RecordCount = data.Orders.Count();  //得到记录数

        PageCount = (int)Math.Ceiling((decimal)RecordCount / 10);   //以10条记录为一页,计算总页码

        int page = 1;

        if (!string.IsNullOrEmpty(Request.QueryString["page"]))

            page = Convert.ToInt16(Request.QueryString["page"]);

        SkipIndex = (page-1) * 10;   //计算起始索引,以供后面的Skip扩展方法之用

        //拼接分页代码

        StringBuilder sb = new StringBuilder();

        for (int i = 1; i < PageCount; i++)

        {

            sb.AppendFormat(@" {0} ",i);

        }

        _PageString = sb.ToString();

        bind();

    }

    void bind()

    {

        //奇妙的Linq表达式

        var q = (from c in data.Orders select new

                { CustomerID = c.CustomerID, ShipAddress=c.ShipAddress,ID = c.OrderID}

               ).Skip(SkipIndex).Take(10);

        this.GridView1.DataSource = q;

        this.GridView1.DataBind();

    }

当显示的是第一页时,看linq表达式中为我们动态生成了什么样的语句:

SELECT TOP 10 [t0].[CustomerID], [t0].[ShipAddress], [t0].[OrderID] AS [ID]
FROM [dbo].[Orders] AS [t0]

是不是觉得非常熟悉?
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