利用AJAX实现无刷新分页技术原理:
其主要是利用AJAX的异步处理机制,实现数据的异步传递,它隐藏了客户端向服务端请求数据的状态,在客户端表现为无刷新的显示状态。
实现分页的步骤:
1.客服端点击页码按钮触发分页事件
2.客户端传递页码参数到服务端
3.服务端连接数据库获取数据
4.服务端将数据序列化并写入输出流
5.客户端获取输出流,并转换为JSON格式数据
6.将JSON数据组合排列到标签元素生成具体页面。
具体实例:
ASPX页面代码
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script type="text/javascript" src="jquery-1.4.1.js"></script>
<script type="text/javascript">
var pageCount = 0;
var pageIndex = 1;
$(function () {
//getdata
$.post("Pager.ashx", { "data": "getdata", "count": "1" }, function (data, status) {
var dd = $.parseJSON(data);
$(".con li").remove();
for (var i = 0; i < dd.length; i++) {
var li = $("<li>" + dd[i].datetime + ":" + dd[i].Msg + "</li>");
$(".con").append(li);
}
});
//getdatacount
$.post("Pager.ashx", { "data": "getcount" }, function (data, status) {
//alert(data);
pageCount = data;
$(".b").text(data);
});
//尾页
$(".pp li:eq(0) a").click(function (e) {
e.preventDefault();
$.post("Pager.ashx", { "data": "getdata", "pagecount": pageCount }, function (data, status) {
var dd = $.parseJSON(data);
$(".con li").remove();
for (var i = 0; i < dd.length; i++) {
var li = $("<li>" + dd[i].datetime + ":" + dd[i].Msg + "</li>");
$(".con").append(li);
}
});
});
//下页
$(".pp li:eq(1) a").click(function (e) {
e.preventDefault();
if (pageIndex < pageCount) {
pageIndex++;
$.post("Pager.ashx", { "data": "getdata", "pagecount": pageIndex }, function (data, status) {
var dd = $.parseJSON(data);
$(".con li").remove();
for (var i = 0; i < dd.length; i++) {
var li = $("<li>" + dd[i].datetime + ":" + dd[i].Msg + "</li>");
$(".con").append(li);
}
});
}
});
//上一页
$(".pp li:eq(2) a").click(function (e) {
e.preventDefault();
if (pageIndex > 1) {
pageIndex--;
$.post("Pager.ashx", { "data": "getdata", "pagecount": pageIndex }, function (data, status) {
var dd = $.parseJSON(data);
$(".con li").remove();
for (var i = 0; i < dd.length; i++) {
var li = $("<li>" + dd[i].datetime + ":" + dd[i].Msg + "</li>");
$(".con").append(li);
}
});
}
});
//首页
$(".pp li:eq(3) a").click(function (e) {
e.preventDefault();
pageIndex = 1;
$.post("Pager.ashx", { "data": "getdata", "pagecount": pageIndex }, function (data, status) {
var dd = $.parseJSON(data);
$(".con li").remove();
for (var i = 0; i < dd.length; i++) {
var li = $("<li>" + dd[i].datetime + ":" + dd[i].Msg + "</li>");
$(".con").append(li);
}
});
});
})
</script>
<style type="text/css">
li{ float:right; margin:0 2px 0; list-style:none;}
.page{float:right; margin-right:1em;}
.content{ clear:both;}
.con li{ float:none; list-style:none; background-color:Gray;}
a{ cursor:pointer;}
.con
{
width: 400px;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div class="content" style=" width:600px; height:400px; border:1px solid red;">
<ul class="con"></ul>
</div>
<div>
<ul class="pp">
<li><a>尾页</a></li>
<li><a>下一页</a></li>
<li><a>上一页</a></li>
<li><a>首页</a></li>
<li><div class="page">共有数据:<span class="b"></span></div></li>
</ul>
</div>
</form>
</body>
</html>
后台处理程序ashx
<%@ WebHandler Language="C#" class="Pager" %>
using System;
using System.Web;
using System.Collections.Generic;
using System.Web.Script.Serialization;
using System.Data;
using System.Data.SqlClient;
using System.Text;
public class Pager : IHttpHandler {
public void ProcessRequest (HttpContext context) {
context.Response.ContentType = "text/plain";
string paras = context.Request.Params["data"].ToString();
//string pagecount = ;
if (paras == "getcount")
{
fenyeSlect ff = new fenyeSlect();
DataTable dt = ff.selectCount().Tables[0];
int count = Convert.ToInt32(dt.Rows[0][0].ToString());
int pageCount = count / 10;
if (count % 10 != 0)
{
pageCount++;
}
context.Response.Write(pageCount);
}
else if (paras == "getdata")
{
string pagenum = context.Request.Params["count"].ToString();
int ipagenum = Convert.ToInt32(pagenum);
fenyeSlect ff = new fenyeSlect();
DataSet ds = ff.GetPageData((ipagenum - 1) * 10 + 1, (ipagenum) * 10);
DataTable dt = ds.Tables[0];
List<News> list = new List<News>();
// string[] list00=new string[dt.Rows.Count];
for (int row = 0; row < dt.Rows.Count; row++)
{
// list00[row] = dt.Rows[row][1].ToString();
list.Add(new News { datetime = dt.Rows[row][1].ToString(), Msg = dt.Rows[row][2].ToString(), ID = dt.Rows[row][0].ToString() });
}
JavaScriptSerializer jss = new JavaScriptSerializer();
string data = jss.Serialize(list);
context.Response.Write(data);
}
//context.Response.Write("Hello World");
}
public bool IsReusable {
get {
return false;
}
}
public class fenyeSlect
{
public SqlConnection getconn()
{
string con = "server=.;uid=sa;pwd=nexel;database=wsxfy;";
SqlConnection conn = new SqlConnection(con);
return conn;
}
/// <summary>
/// 获得条数,有多少条数据
/// </summary>
/// <returns></returns>
public DataSet selectCount()
{
string selectCount = "SELECT COUNT(*) FROM T_Comment";
DataSet ds = new DataSet();
SqlConnection conn = getconn();
conn.Open();
SqlDataAdapter da = new SqlDataAdapter(selectCount, conn);
da.Fill(ds);
return ds;
}
public DataSet GetPageData(int StartRowIndex, int EndRowIndex)
{
// string fenye = "select * from (select ID,Title,Person,[Time],Row_Number() over(order by ID desc) rownum from tb_IndustryNews)t where t.rownum>="+StartRowIndex+" and t.rownum<="+EndRowIndex+"";
StringBuilder sql = new StringBuilder();
sql.Append("select * from ( ");
sql.Append("select ID,PostDate,Msg,Row_Number() over(order by ID desc) Rownum from T_Comment ");
sql.Append(")t ");
sql.Append("where t.Rownum>='" + StartRowIndex + "' and t.Rownum<='" + EndRowIndex + "'");
DataSet ds = new DataSet();
SqlConnection conn = getconn();
conn.Close();
SqlDataAdapter da = new SqlDataAdapter(sql.ToString(), conn);
da.Fill(ds);
return ds;
}
}
public class News
{
public string datetime { get; set; }
public string Msg { get; set; }
public string ID { get; set; }
}
}