jQuery getJSON()+.ashx 实现分页(改进版)_jquery

参考了：http://www.jb51.net/article/35110.htm
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：

复制代码 代码如下:

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

二、.html页

复制代码 代码如下:

上一页   
下一页

三、.ashx页

复制代码 代码如下:

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
 
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备注 (2010-7-10)：
用sql2005 row_number()分页方法，.ashx页面代码可简化为

复制代码 代码如下:

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 rowNumDataTable 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