掌握要点: <IList>,DataGrid翻页事件...
详细代码如下,慢慢体会..
using System;
using System.Collections;
using System.Collections.Specialized;
using System.Text;
using System.Text.RegularExpressions;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace CustomControl


{

/**//// <summary>
/// CustomList 的摘要说明
/// 重构DataList控件
/// </summary>
public class CustomList : DataList

{
//静态常量
protected const string HTML1 = "<table width=100% cellpadding=0 cellspacing=0><tbody><tr><td>";
protected const string HTML2 = "</td></tr><tr><td align=right>";
//protected const string HTML3 = "</td><td align=center class=paging>";

//protected const string HTML5 = "</td><td align=right class=paging>";

protected const string HTML4 = "</td></tr></tbody></table>";

private static readonly Regex RX = new Regex(@"^&page=\d+", RegexOptions.Compiled);
private const string LINK_PREV = "<a href=?page={0}>前一页</a>";
private const string LINK_MORE = "<a href=?page={0}>下一页</a>";
private const string LINK_FIRST = "<a href=?page={0}>首页</a>"; //首页
private const string LINK_LAST = "<a href=?page={0}>尾页</a>"; //尾页
private const string KEY_PAGE = "page";
private const string COMMA = "?";
private const string AMP = "&";

protected string emptyText;
private IList dataSource; //数据源
private int pageSize = 10; //每页大小
private int currentPageIndex; //当前页
private int itemCount; //数据条目总数


/**//// <summary>
/// 指定要绑定的数据源
/// </summary>
override public object DataSource

{
set

{
//This try catch block is to avoid issues with the VS.NET designer
//The designer will try and bind a datasource which does not derive from ILIST
try

{
dataSource = (IList)value;
ItemCount = dataSource.Count;
}
catch

{
dataSource = null;
ItemCount = 0;
}
}
}


/**//// <summary>
/// 每页大小
/// </summary>
public int PageSize

{

get
{ return pageSize; }

set
{ pageSize = value; }
}


/**//// <summary>
/// 总页数
/// </summary>
protected int PageCount

{

get
{ return (ItemCount - 1) / pageSize; }
}


/**//// <summary>
/// 可重载,数据条目总数
/// </summary>
virtual protected int ItemCount

{

get
{ return itemCount; }

set
{ itemCount = value; }
}


/**//// <summary>
/// 可重载,当前页码
/// </summary>
virtual public int CurrentPageIndex

{

get
{ return currentPageIndex; }

set
{ currentPageIndex = value; }
}


/**//// <summary>
/// 空Text
/// </summary>
public string EmptyText

{

set
{ emptyText = value; }
}


/**//// <summary>
/// 设置页面,翻页事件
/// </summary>
/// <param name="index"></param>
public void SetPage(int index)

{
OnPageIndexChanged(new DataGridPageChangedEventArgs(null, index));
}

override protected void OnLoad(EventArgs e)

{
if (Visible)

{
string page = Context.Request[KEY_PAGE];
int index = (page != null) ? int.Parse(page) : 0;
SetPage(index);
}
}



/**//// <summary>
/// Overriden method to control how the page is rendered
/// Render提交写入
/// </summary>
/// <param name="writer"></param>
override protected void Render(HtmlTextWriter writer)

{

//Check there is some data attached
if (ItemCount == 0)

{
writer.Write(emptyText);
return;
}

//Mask the query "?"/"&"二个符号
string query = Context.Request.Url.Query.Replace(COMMA, AMP);
//正则表达式替换
query = RX.Replace(query, string.Empty);


// Write out the first part of the control, the table header
writer.Write(HTML1);

// Call the inherited method
base.Render(writer);

// Write out a table row closure
writer.Write(HTML2);

if (currentPageIndex > 0)
writer.Write(string.Format(LINK_FIRST, 0 + query) + " "); //首页
//Determin whether next and previous buttons are required
//Previous button?
if (currentPageIndex > 0)
writer.Write(string.Format(LINK_PREV, (currentPageIndex - 1) + query));

//Close the table data tag
//writer.Write(HTML3);

//当前页/总页数
writer.Write(" " + string.Format("页码:{0}/{1}", currentPageIndex + 1, PageCount + 1) + " ");

//writer.Write(HTML5);

//Next button?
if (currentPageIndex < PageCount)
writer.Write(string.Format(LINK_MORE, (currentPageIndex + 1) + query));
if (currentPageIndex < PageCount)
writer.Write(" " + string.Format(LINK_LAST, PageCount + query)); //尾页

//Close the table
writer.Write(HTML4);
}

override protected void OnDataBinding(EventArgs e)

{

//Work out which items we want to render to the page
int start = CurrentPageIndex * pageSize;
int size = Math.Min(pageSize, ItemCount - start);

IList page = new ArrayList();

//Add the relevant items from the datasource
for (int i = 0; i < size; i++)
page.Add(dataSource[start + i]);

//set the base objects datasource
base.DataSource = page;
base.OnDataBinding(e);

}


/**//// <summary>
/// 翻页事件
/// </summary>
public event DataGridPageChangedEventHandler PageIndexChanged;


/**//// <summary>
/// 可重载,翻页事件处理
/// </summary>
/// <param name="e"></param>
virtual protected void OnPageIndexChanged(DataGridPageChangedEventArgs e)

{
if (PageIndexChanged != null)
PageIndexChanged(this, e);
}
}
}