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  • jQuery getJSON() + .ashx 实现分页

    参考了:http://www.cnblogs.com/xingshao/archive/2009/09/11/1564938.html

    改进的地方:

    1、ashx返回json数据,减少传输数据量,html页面样式控制也比较灵活;

    2、改写html页的jQuery代码;

    3、把3个ashx文件简化为1个。

    一、创建表的测试数据:

    create table test(id int identity,title varchar(36))
    declare @index int;
    set @index = 1;
    while(@index < 8888)
    begin
        insert test(title) values (newid())
        set @index = @index + 1
    end

    二、.html页

    <html xmlns="http://www.w3.org/1999/xhtml" >
    <head runat="server"> 
        <title></title>
         <script type="text/javascript" src="jquery-1.4.2.min.js"></script>
         <script type="text/javascript">
             $(function() {
                 Init();
             });
             function Init() {
                 $("#Content").html("");
                 $("#pageIndex").val(0);
                 $("#pageInfo").append("当前第1页");
                 $.getJSON("Handler.ashx", { type: 'first' }, function(data) {
                     $("#Content").append("<tr><th style='130px'>id</th><th style='150px'>title</th></tr>");
                     $.each(data, function(i) {
                         $("#Content").append("<tr><td>" + data[i].id + "</td><td>" + data[i].title + "</td></tr>");
                     })
                 })
             }        
             function Pre() {         
                 var currIndex = Number($("#pageIndex").val()) - 1;            
                 Go('pre', currIndex);
             }
             function Next() {
                 var currIndex = Number($("#pageIndex").val()) + 1;
                 Go('next', currIndex);
             }
             function Go(type, index) {
                 $("#Content").html("");
                 $("#pageInfo").html("");
                 if (index == 0 || index == -1) { Init(); return; }
                 $.getJSON("Handler.ashx", { type: type, index: index }, function(data) {
                     $("#Content").append("<tr><th style='130px'>id</th><th style='150px'>title</th></tr>");
                     $.each(data, function(i) {
                         $("#Content").append("<tr><td>" + data[i].id + "</td><td>" + data[i].title + "</td></tr>");
                     })
                     $("#pageInfo").append("当前第 " + (index + 1) + " 页");
                     $("#pageIndex").val(index);
                 });
             }
         </script>
    </head>
    <body>
        <form id="form1" runat="server">      
            <div style=" 100%">
               <table id="Content" >                          
               </table>
            </div>
            <div id="PagePanel" style="margin-left:20px">
                <label id="pageInfo"></label>          
                <a href="#" onclick="Pre()">上一页</a>&nbsp; &nbsp;
                <a href="#" onclick="Next()">下一页</a>
            </div>
            <input type="hidden" value="0" id="pageIndex" />
        </form>
    </body>
    </html>

    三、.ashx页

    public class Handler : IHttpHandler
        {
            public void ProcessRequest(HttpContext context)
            {
                context.Response.ContentType = "text/plain";
                StringBuilder tb = new StringBuilder();
                DataBase db = new DataBase();
                int pageSize = 10;
                int pageIndex = 0;

                string type = context.Request.Params["type"];
                switch (type)
                {               
                    case "first":
                        DataTable dt1 = db.GetDataSet("select top 10 * from test", null).Tables[0];
                        tb.Append(Common.DataTableToJSON(dt1, true)); //DataTable转为JSON
                        break;
                    case "next":                   
                        pageIndex = Convert.ToInt32(context.Request.Params["index"]);
                        DataTable dt2 = db.GetDataSet("select top " + pageSize.ToString() + " * from test where id> (select max(id) from (select top " + (pageSize * pageIndex).ToString() + " id from test) t)", null).Tables[0];
                        tb.Append(Common.DataTableToJSON(dt2, true));
                        break;
                    case "pre":                   
                        pageIndex = Convert.ToInt32(context.Request.Params["index"]);
                        DataTable dt3 = db.GetDataSet("select top " + pageSize.ToString() + " * from test where id> (select max(id) from (select top " + (pageSize * pageIndex).ToString() + " id from test) t)", null).Tables[0];
                        tb.Append(JSONHelper.DataTableToJSON(dt));
                        break;
                }

                context.Response.Write(tb.ToString());
            }

            public bool IsReusable
            {
                get
                {
                    return false;
                }
            }
        }


    四、效果

    id title
    11 12937A34-8EFA-4703-946A-FDE12BC3F5AB
    12 DAF9D2AC-3BEE-4BF6-955A-CA57EC2D1281
    13 F9DB3478-AE84-42AB-9A49-F02363EEECE8
    14 5E67126F-20B8-40BF-9E38-A45665E2B247
    15 6F25D12F-CF24-43B0-A1A6-ED917B8466C8
    16 9464242D-B0C6-407C-8779-4C15BD64E474
    17 AB7A7DB3-A117-41B4-8EF2-00F01ACF1058
    18 9A332F56-9C23-45B1-B49B-4E62095870ED
    19 829D803D-5288-4B71-AB35-3C6A32352F29
    20 307E8ABA-D975-4F01-AC4F-25F50A4CA52A
    上一页     下一页




    --------------------------------------------------------------------------------------------------------------------

    备注 (2010-7-10)

    用sql2005 row_number()分页方法,.ashx页面代码可简化为

     public class Handler : IHttpHandler
        {
            public void ProcessRequest(HttpContext context)
            {
                context.Response.ContentType = "text/plain";
               
                DataBase db = new DataBase();
                int pageSize = 10;
                int pageIndex = 0;
                int.TryParse(context.Request.Params["index"], out pageIndex);
                string type = context.Request.Params["type"];
               
                string sql = string.Format("select * from ( select row_number() over (order by id) as rowNum,* from test) as t "
                    + " where rowNum>{0} and rowNum<={1}", pageIndex * pageSize, (pageIndex+1) * pageSize);

                DataTable dt = db.GetDataSet(sql, null).Tables[0];    

                context.Response.Write(JSONHelper.DataTableToJSON(dt));
            }

            public bool IsReusable
            {
                get
                {
                    return false;
                }
            }
        }

    备注:

    其中JSONHelper.DataTableToJSON(dt)方法为DataTable解析成JSON,见另一篇文章JSONHelper 帮助类

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  • 原文地址:https://www.cnblogs.com/gdjlc/p/2086896.html
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