jQuery getJSON() .ashx implements paging (improved version)_jquery

Reference: http://www.jb51.net/article/35110.htm
Improvements:
1. ashx returns json data, reducing the amount of transmitted data, and html page style control It is also more flexible;
2. Rewrite the jQuery code of the html page;
3. Simplify 3 ashx files into 1.
1. Create test data for the table:

Copy the code The code is as follows:

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

2. .html page

Copy code The code is as follows:

< form id="form1" runat="server">

Previous page
Next page< ;/a>

The code is as follows:

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 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