Eric的超高效数据分页(图示+代码) ^_^

数据表结构:
megaid int IDENTITY (1, 1) NOT NULL PRIMARY KEY  CLUSTERED
megaguid char (36) NOT NULL INDEX
数据生成脚本:

DECLARE @i int
SET @i = 1
WHILE @i < 1000001
    BEGIN
        INSERT INTO megatable (megaguid) VALUES(NEWID())
        SET @i = @i + 1
    END
GO

C#代码:

 DateTime startTime;

        void Page_Init(Object sender, EventArgs e)
        {
            startTime = DateTime.Now;
        }

        protected override void Render(HtmlTextWriter writer)  
        {
            base.Render(writer); 
            Response.Write("本页执行时间: "  +  (DateTime.Now - startTime));  
        }

        int records = 10000;
        int pages = 10;
        int pageSize = 15;
        SqlConnection conn = new SqlConnection("Server=(local);Database=megadata;User Id=sa;Password=xxx");

        void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                dgBind(getSqlString(1));
            }

            int firstPage = int.Parse(hidFirstPage.Value);
            pnlButtons.Controls.Add(getPager(firstPage));
            lblPrompt.Text = "数据提取范围: <B>SELECT TOP " + records.ToString() + " megaid FROM megatable ORDER BY megaguid</B>";
        }

        string getSqlString(int selectedPage)
        {
            string[] idsStrArray;
            string sqlStr;

            if (Session["idStr"] != null)
            {
                idsStrArray = Session["idStr"].ToString().Split('#');
            }
            else
            {
                sqlStr = "SELECT TOP " + records.ToString() + " megaid FROM megatable ORDER BY megaguid";
                SqlCommand cmd = new SqlCommand(sqlStr, conn);
                conn.Open();
                SqlDataReader dr = cmd.ExecuteReader();
                StringBuilder sb = new StringBuilder("");
                int n = 1;

                while (dr.Read())
                {
                    if (n % pageSize == 0)
                    {
                        sb.Append(dr[0].ToString() + "#");
                    }
                    else
                    {
                        sb.Append(dr[0].ToString() + ",");
                    }
                    
                    n++;
                }

                dr.Close();
                conn.Close();
                sb.Remove(sb.Length - 1, 1);
                idsStrArray = sb.ToString().Split('#');
                Session["idStr"] = sb.ToString();
            }

            hidPageCount.Value = idsStrArray.Length.ToString();
            sqlStr = "SELECT megaid, megaguid FROM megatable WHERE megaid IN (" + idsStrArray[selectedPage - 1] + ") ";
            sqlStr += "ORDER BY megaguid";
            return sqlStr;
        }
        
        Panel getPager(int firstPage)
        {
            int pageCount = int.Parse(hidPageCount.Value);
            Panel pnlPager = new Panel();
            pnlPager.Controls.Add(new LiteralControl("<BR> 共" + pageCount.ToString() + "页 "));
            pnlPager.Controls.Add(getLinkButton("Fst", "首页", "pgBtn", "1"));
            pnlPager.Controls.Add(new LiteralControl(" "));

            if (firstPage > 0)
            {
                pnlPager.Controls.Add(getLinkButton("Pre", "前" + pages.ToString() + "页", "pgBtn", (firstPage - pages + 1).ToString()));
                pnlPager.Controls.Add(new LiteralControl(" "));
            }

            for (int i = firstPage + 1; i < firstPage + pages + 1; i++)
            {
                if (i > pageCount)
                {
                    break;
                }
                
                pnlPager.Controls.Add(getLinkButton(i.ToString(), "[" + i.ToString() + "]", "pgBtn", i.ToString()));
                pnlPager.Controls.Add(new LiteralControl(" "));
            }

            if (firstPage + pages < pageCount)
            {
                pnlPager.Controls.Add(getLinkButton("Nxt", "后" + pages.ToString() + "页", "pgBtn", (firstPage + pages + 1).ToString()));
                pnlPager.Controls.Add(new LiteralControl(" "));
            }

            pnlPager.Controls.Add(getLinkButton("Lst", "末页", "pgBtn", pageCount.ToString()));
            return pnlPager;
        }

        LinkButton getLinkButton(string lbId, string lbText, string lbCmdName, string lbCmdArg)
        {
            LinkButton lb = new LinkButton();
            lb.ID = lbCmdName + lbId;
            lb.Text = lbText;
            lb.CommandName = lbCmdName;
            lb.CommandArgument = lbCmdArg;
            lb.Command += new CommandEventHandler(pageTurn);
            return lb;
        }
        
        void pageTurn(object sender, CommandEventArgs e)
        {
            LinkButton lb = (LinkButton)sender;
            int selectedPage = int.Parse(lb.CommandArgument);
            int firstPage = selectedPage / pages * pages;
            firstPage = (selectedPage % pages == 0) ? (firstPage - pages) : firstPage;
            hidFirstPage.Value = firstPage.ToString();
            dgBind(getSqlString(selectedPage));
            pnlButtons.Controls.RemoveAt(pnlButtons.Controls.Count - 1);
            pnlButtons.Controls.Add(getPager(firstPage));
            lb = (LinkButton)pnlButtons.Controls[pnlButtons.Controls.Count - 1].FindControl("pgBtn" + selectedPage.ToString());
            lb.Enabled = false;
        }
        
        void dgBind(string sqlStr)
        {
            SqlDataAdapter da = new SqlDataAdapter(sqlStr, conn);
            DataTable dt = new DataTable();
            conn.Open();
            da.Fill(dt);
            conn.Close();
            da.Dispose();
            dg.DataSource = dt;
            dg.DataBind();
        }

        void dg_ItemDataBound(object sender, DataGridItemEventArgs e)
        {
            dg.Controls[0].EnableViewState = false;
        }

ASPX代码:

<%@ Import Namespace="System.Text" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<%@ Import Namespace="System.Data" %>
<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<HTML>
    <HEAD>
        <TITLE>Pager</TITLE>
        <SCRIPT runat="server">
        //插入上面的C#代码
        </SCRIPT>
        <STYLE>BODY {}{ FONT-SIZE: 9pt; FONT-FAMILY: Tahoma,宋体; TEXT-ALIGN: center }
    TD {}{ FONT-SIZE: 9pt; FONT-FAMILY: Tahoma,宋体; TEXT-ALIGN: center }
    </STYLE>
    </HEAD>
    <BODY>
        <FORM id="form1" runat="server">
            <DIV>
                <ASP:LABEL id="lblPrompt" runat="server" text="?" enableviewstate="False" enabletheming="True"></ASP:LABEL>
                <BR>
                <ASP:PANEL id="pnlButtons" runat="server" width="560px">
                    <INPUT id="hidFirstPage" type="hidden" value="0" runat="server"><INPUT id="hidPageCount" type="hidden" runat="server">
                    <ASP:DATAGRID id="dg" runat="server" width="100%" onitemdatabound="dg_ItemDataBound" cellpadding="4"
                        backcolor="White" borderwidth="1px" borderstyle="None" bordercolor="#CC9966" autogeneratecolumns="False"
                        pagesize="5">
                        <FOOTERSTYLE forecolor="#330099" backcolor="#FFFFCC"></FOOTERSTYLE>
                        <HEADERSTYLE font-bold="True" forecolor="#FFFFCC" backcolor="#990000"></HEADERSTYLE>
                        <PAGERSTYLE horizontalalign="Center" forecolor="#330099" backcolor="#FFFFCC"></PAGERSTYLE>
                        <SELECTEDITEMSTYLE font-bold="True" forecolor="#663399" backcolor="#FFCC66"></SELECTEDITEMSTYLE>
                        <ITEMSTYLE forecolor="#330099" backcolor="White"></ITEMSTYLE>
                        <COLUMNS>
                            <ASP:BOUNDCOLUMN datafield="megaid" headertext="MegaID"></ASP:BOUNDCOLUMN>
                            <ASP:BOUNDCOLUMN datafield="megaguid" headertext="MegaGUID"></ASP:BOUNDCOLUMN>
                        </COLUMNS>
                    </ASP:DATAGRID>
                </ASP:PANEL></DIV>
            <BR>
            <ASP:HYPERLINK id="lnkReload" runat="server" width="80px" navigateurl="Pager.aspx" enableviewstate="False">重载</ASP:HYPERLINK>
        </FORM>
    </BODY>
</HTML>