asp分页根本原理

<%
dir="../"
channel="product"
%><% action = "http://" & Request.ServerVariables("HTTP_HOST")%>
<% bid=request("bid")
sid=request("sid")
if bid<>"" then
p_name=conn.execute("select type_name from mm_product_bigclass where then

s_name=conn.execute("select type_name from mm_product_smallclass where then

s_name="产品中心"
end if%><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />
<TITLE><%p_name%> <%=s_name%>--<%=enweb_name%></TITLE>

<link rel="stylesheet" type="text/css" href="../jiasheng.css"/>
<SCRIPT language=JavaScript type=text/javascript src="jquery.js"></SCRIPT>
<SCRIPT language=JavaScript type=text/javascript src="preview.js"></SCRIPT>
</head>

<body>

<table width="984" border="0" cellspacing="0" cellpadding="0" style="margin-bottom:30px">
<tr>
    <td width="209" height="278" align="left" valign="top">
     </td>
    <td align="center" valign="top"><table width="770" height="320" border="0" cellpadding="0" cellspacing="0">
      <tr>
        <td align="left" valign="top" class="table" height="40"><img src="../images/icon.jpg" width="19" height="24" /><img src="../images/products.gif" width="130" height="22" /></td>
      </tr>
      <tr>
        <td align="left" valign="top" class="font13" style=" padding-top:10px; padding-bottom:10px;">
        <%const recpage=12
if not isempty(request("page")) then
currentpage=cint(request("page"))
else
currentpage=1
end if
if request("page")="" or request("page")<1 then
currentpage=1
end if
    sql1=""
if bid<>"" then
sql1=" and product_bigclass="&bid&" "
end if
if sid<>"" then
sql1=" and product_smallclass="&sid&" "
end if

set rs=server.createobject("adodb.recordset")
rs.open "select count(*) AS co from product where 1=1 "&sql1,conn,3,1
allrec=rs("co")
totalpage=int((allrec+recpage-1)/recpage)
rs.close
set rs=nothing
set rs=server.createobject("adodb.recordset")
if currentpage=1 then
sql="select top "&recpage&" * from product where 1=1 "&sql1&" order by id desc"
else
sql="select top "&recpage&" * from product where 1=1 and id not in (select top "&(recpage*(currentpage-1))&" id from product where 1=1 "&sql1&" order by id desc) "&sql1&" order by id desc"
end if
rs.open sql,conn,1,1
%> <%do while not rs.eof%>
<div class="productdiv">
<div )%></a></span></div>

          <%
rs.movenext

loop

%></td>
      </tr>
      <tr>
        <td height="40" align="center" valign="middle" class="font13" style="padding-left:4px; border-top:#CCCCCC 1px solid"><div class="page">
<form method="post" name="forms"
        End If
    Next
n=currentpage+1
p=currentpage-1

if p<= 0 then
p=1
end if

if n>= totalpage then
n=totalpage
end if

minpage=currentpage-5
maxpage=currentpage+5

if minpage<= 0 then
minpage=1
maxpage=10
end if
if maxpage >totalpage then
maxpage=totalpage
minpage=maxpage-9
if minpage<= 0 then
minpage=1
end if
end if
%>
<div class="scott" >
<div align="center">
    <%
response.write(" Total<font color=red> "&allrec&" </font>个")
response.Write(" Page <font color=red>"&currentpage&"</font>/<font color=red>"&totalpage&"</font> ")
%>
      <% if currentpage<>1 then %>
      <a href="index.asp?<%=temp%>page=<%=p%>" style="margin-right:5px;"> < </a>
      <%else%>
      <a style="margin-right:5px;"> < </a>
      <%end if%>
      <%
i=1
for page=minpage to maxpage

if page=currentpage then
%>
      <span class="current"><%=page%></span>
      <%else%>
      <a href="index.asp?<%=temp%>page=<%=page%>" style="color:#FFFFFF"><%=page%></a>
      <%
end if
i=i+1
next
if currentpage<totalpage then
%>
      <a href="index.asp?<%=temp%>page=<%=n%>"> > </a>
      <%else%>
      <a > > </a>
      <%end if%>
      <select name="menu1" onChange="if(this.options[this.selectedIndex].value!=''){location=this.options[this.selectedIndex].value;}" class="input1">
        <%for i=1 to totalpage %>
        <option value="index.asp?<%=temp%>page=<%=i%>" <%if i=currentpage then%> selected="selected" <%end if%>><%=i%></option>
      <%next%>
      </select>
</div>
</div>
</form>

</div></td>
</tr>
</table></td>
</tr>
</table>

</body>
</html>