Eric的超高效数据分页(图示+代码) ^_^

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

        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;
        }

<% @ 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 >