Jquery+json implementation of Ajax two-level linkage case Analysis _jquery

The example of this article describes the method of realizing Ajax two-level linkage with Jquery+json. Share to everyone for your reference, specific as follows:

Backstage Handler.ashx

<%@ WebHandler language= "C #" class= "Handler"%>
using System;
Using System.Web;
Using System.Data;
public class Handler:ihttphandler
{
 Common coobj = new Common ();
 public void ProcessRequest (HttpContext context)
 {
  if (context). request.params["n"]!= null)
  {
   string num = context. request.params["n"]. ToString ();
   Context. Response.ContentType = "Text/plain";
   String str = "SELECT * From address where a_num2=" + num;
   DataTable dt = coobj.gettable (str);
   String json = Jsonhelper.datatabletojson (DT);
   Context. Response.Write (JSON);
  }
 public bool IsReusable
 {
  get
  {return
   false;
}}}

Front desk dropdownlist.html

<!
DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >  

I hope this article will help you with your jquery programming.